Examples with solutions for Solving Equations by using Addition/ Subtraction: Solving an equation with fractions

Exercise #1

a+212=4 a+2\frac{1}{2}=4

a=? a=\text{?}

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Convert the mixed number 2122\frac{1}{2} to an improper fraction.
  • Step 2: Subtract 2122\frac{1}{2} from both sides of the equation to isolate aa.
  • Step 3: Simplify the result to find the value of aa.

Now, let's work through each step:

Step 1: Convert 2122\frac{1}{2} to an improper fraction. 212=522\frac{1}{2} = \frac{5}{2}.

Step 2: The equation becomes a+52=4 a + \frac{5}{2} = 4 . To isolate aa, subtract 52\frac{5}{2} from both sides:

a=452 a = 4 - \frac{5}{2}

Step 3: Convert 4 into a fraction with the same denominator to perform the subtraction. 4=824 = \frac{8}{2}.

a=8252=32 a = \frac{8}{2} - \frac{5}{2} = \frac{3}{2} .

The improper fraction 32\frac{3}{2} can be converted back to a mixed number, giving a=112 a = 1\frac{1}{2} .

Therefore, the solution to the problem is a=112 a = 1\frac{1}{2} .

Answer

a=112 a=1\frac{1}{2}

Exercise #2

b345=835 b-3\frac{4}{5}=-8\frac{3}{5}

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Convert mixed numbers to improper fractions
  • Step 2: Isolate the variable b b by applying algebraic operations
  • Step 3: Simplify the result to find the value of b b

Now, let's work through each step:

Step 1: Convert the mixed numbers to improper fractions.
345=155+45=1953\frac{4}{5} = \frac{15}{5} + \frac{4}{5} = \frac{19}{5}
835=(405+35)=435-8\frac{3}{5} = -\left(\frac{40}{5} + \frac{3}{5}\right) = -\frac{43}{5}

Step 2: Add 195 \frac{19}{5} to both sides of the equation to isolate b b .

b195=435 b - \frac{19}{5} = -\frac{43}{5}

Add 195 \frac{19}{5} to both sides:
b195+195=435+195 b - \frac{19}{5} + \frac{19}{5} = -\frac{43}{5} + \frac{19}{5}
This simplifies to:
b=43+195=245=445 b = \frac{-43+19}{5} = \frac{-24}{5} = -4\frac{4}{5}

Therefore, the solution to the problem is b=445 b = -4\frac{4}{5} .

Answer

b=445 b=-4\frac{4}{5}

Exercise #3

Solve for X:

13x12x=3 \frac{1}{3}x-\frac{1}{2}x=3

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Find a common denominator for the fractions involved.
  • Step 2: Simplify the left-hand side of the equation.
  • Step 3: Solve the resulting equation for xx.

Now, let's work through each step:

Step 1: The given equation is 13x12x=3\frac{1}{3}x - \frac{1}{2}x = 3. The fractions 13\frac{1}{3} and 12\frac{1}{2} need a common denominator. The least common denominator for 3 and 2 is 6.

Step 2: Convert each fraction: 13=26and12=36 \frac{1}{3} = \frac{2}{6} \quad \text{and} \quad \frac{1}{2} = \frac{3}{6} Thus, the equation 13x12x=3\frac{1}{3}x - \frac{1}{2}x = 3 becomes 26x36x=3 \frac{2}{6}x - \frac{3}{6}x = 3 Combine the terms: (2636)x=16x \left(\frac{2}{6} - \frac{3}{6}\right)x = -\frac{1}{6}x So the equation is: 16x=3 -\frac{1}{6}x = 3

Step 3: Solve for xx: To isolate xx, multiply both sides of the equation by 6-6 (the reciprocal of 16-\frac{1}{6}): x=3×(6) x = 3 \times (-6) x=18 x = -18

Therefore, the solution to the problem is x=18 x = -18 .

Answer

18 -18

Exercise #4

Solve for X:

25x+34x=1 \frac{2}{5}x+\frac{3}{4}x=1

Video Solution

Step-by-Step Solution

To solve the equation 25x+34x=1 \frac{2}{5}x + \frac{3}{4}x = 1 , we will follow these steps:

  • Step 1: Find a common denominator to combine the fractions on the left-hand side.
  • Step 2: Simplify the equation.
  • Step 3: Isolate the variable x x .

Now, let's work through each step:
Step 1: The denominators are 5 and 4. The least common denominator (LCD) is 20.
Convert each term: 25=2×45×4=820 \frac{2}{5} = \frac{2 \times 4}{5 \times 4} = \frac{8}{20} and 34=3×54×5=1520 \frac{3}{4} = \frac{3 \times 5}{4 \times 5} = \frac{15}{20} .

Step 2: Combine the fractions: 820x+1520x=2320x \frac{8}{20}x + \frac{15}{20}x = \frac{23}{20}x .
The equation now is 2320x=1 \frac{23}{20}x = 1 .

Step 3: Solve for x x by multiplying both sides by the reciprocal of 2320 \frac{23}{20} , which is 2023 \frac{20}{23} .
Thus, x=1×2023=2023 x = 1 \times \frac{20}{23} = \frac{20}{23} .

Therefore, the solution to the equation is 2023 \boxed{\frac{20}{23}} .

Answer

2023 \frac{20}{23}

Exercise #5

Solve for X:

18x+23x=3 \frac{1}{8}x+\frac{2}{3}x=3

Video Solution

Step-by-Step Solution

To solve the equation 18x+23x=3 \frac{1}{8}x + \frac{2}{3}x = 3 , we need to clear the fractions by finding the least common denominator.

Step 1: Identify the least common denominator of the fractions.
The denominators are 8 and 3. The least common denominator (LCD) is 24.

Step 2: Rewrite the equation with the LCD to get rid of the fractions:
Multiply each term by 24:
24×18x+24×23x=24×3 24 \times \frac{1}{8} x + 24 \times \frac{2}{3} x = 24 \times 3 .

Step 3: Simplify each term:
248x=3x \frac{24}{8}x = 3x ,
243x=16x \frac{24}{3}x = 16x ,
Thus, the equation becomes 3x+16x=72 3x + 16x = 72 .

Step 4: Combine like terms:
19x=72 19x = 72 .

Step 5: Solve for x x by dividing both sides by 19:
x=7219 x = \frac{72}{19} .

Convert the improper fraction to a mixed number:
Divide 72 by 19, which gives 3 with a remainder of 15. Thus, x=31519 x = 3\frac{15}{19} .

Therefore, the solution to the problem is x=31519 x = 3\frac{15}{19} .

Answer

31519 3\frac{15}{19}

Exercise #6

Solve for X:

27x23x=4 \frac{2}{7}x-\frac{2}{3}x=4

Video Solution

Step-by-Step Solution

To solve the provided equation 27x23x=4 \frac{2}{7}x - \frac{2}{3}x = 4 , we need to combine like terms on the left-hand side. Let's work step-by-step:

  • Step 1: Identify the common denominator of the fractions 27 \frac{2}{7} and 23 \frac{2}{3} .
    The least common denominator of 7 and 3 is 21.

  • Step 2: Rewrite each term with the common denominator of 21:
    27x=2×37×3x=621x\frac{2}{7}x = \frac{2 \times 3}{7 \times 3}x = \frac{6}{21}x and
    23x=2×73×7x=1421x\frac{2}{3}x = \frac{2 \times 7}{3 \times 7}x = \frac{14}{21}x.

  • Step 3: Combine these like terms:
    621x1421x=61421x=821x\frac{6}{21}x - \frac{14}{21}x = \frac{6 - 14}{21}x = \frac{-8}{21}x.

  • Step 4: Rewrite the equation with the combined terms:
    821x=4\frac{-8}{21}x = 4.

  • Step 5: Solve for x x by multiplying both sides by the reciprocal of 821-\frac{8}{21}:
    x=4×218=4×218=848=10.5x = 4 \times \frac{21}{-8} = 4 \times -\frac{21}{8} = -\frac{84}{8} = -10.5 or 1012-10\frac{1}{2}.

Therefore, the solution to the equation is x=1012 x = -10\frac{1}{2} .

Answer

1012 - 10\frac{1}{2}

Exercise #7

Solve for X:

14x23x+18x=5 \frac{1}{4}x-\frac{2}{3}x+\frac{1}{8}x=5

Video Solution

Step-by-Step Solution

Solve the equation by following these steps:

  • Step 1: Find the least common multiple (LCM) of the denominators 44, 33, and 88. The LCM is 2424.
  • Step 2: Rewrite each term so that the denominator is 2424.
    14x=624x\frac{1}{4}x = \frac{6}{24}x
    23x=1624x-\frac{2}{3}x = -\frac{16}{24}x
    18x=324x\frac{1}{8}x = \frac{3}{24}x
  • Step 3: Combine the terms over the common denominator:
    (6241624+324)x=5\left(\frac{6}{24} - \frac{16}{24} + \frac{3}{24}\right)x = 5
  • Step 4: Simplify the left side:
    616+324x=5\frac{6 - 16 + 3}{24}x = 5
    724x=5 \frac{-7}{24}x = 5
  • Step 5: Solve for xx by isolating it:
    Multiply both sides by 24/7-24/7:
    x=5×(247)x = 5 \times \left(-\frac{24}{7}\right)
  • Step 6: Perform the multiplication:
    x=1207x = -\frac{120}{7}
  • Step 7: Convert the improper fraction to a mixed number:
    The mixed number is 1717-17\frac{1}{7}.

The solution to the equation is x=1717 x = -17\frac{1}{7} .

Answer

1717 -17\frac{1}{7}

Exercise #8

Solve for X:

14x+23x16x=2 -\frac{1}{4}x+\frac{2}{3}x-\frac{1}{6}x=2

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the common denominator.
  • Step 2: Rewrite the equation with the common denominator.
  • Step 3: Combine like terms.
  • Step 4: Solve the simplified equation for x x .

Now, let's work through each step:

Step 1: The denominators of the fractions are 4, 3, and 6. The least common denominator is 12.

Step 2: Rewrite each term with the common denominator:

  • 14x=312x-\frac{1}{4}x = -\frac{3}{12}x
  • 23x=812x\frac{2}{3}x = \frac{8}{12}x
  • 16x=212x-\frac{1}{6}x = -\frac{2}{12}x

Step 3: Combine the fractions:

312x+812x212x=2-\frac{3}{12}x + \frac{8}{12}x - \frac{2}{12}x = 2

This simplifies to 312x=2\frac{3}{12}x = 2.

Step 4: Simplify and solve for x x :

Multiply both sides by 12 to clear the denominator:

3x=243x = 24

Divide both sides by 3:

x=8x = 8

Therefore, the solution to the problem is x=8 x = 8 .

Answer

8 8

Exercise #9

Solve for X:

18x23x+15x=1 \frac{1}{8}x-\frac{2}{3}x+\frac{1}{5}x=1

Video Solution

Step-by-Step Solution

The common denominator of 8, 3, and 5 is 120.

Now we multiply each numerator by the corresponding number to reach 120 and thus cancel the fractions and obtain the following equation:

(1×x×15)(2×x×40)+(1×x×24)=1×120 (1\times x\times15)-(2\times x\times40)+(1\times x\times24)=1\times120

We multiply the exercises in parentheses accordingly:

15x80x+24x=120 15x-80x+24x=120

We will solve the left side (from left to right) and will obtain:

(15x80x)+24x=120 (15x-80x)+24x=120

65x+24x=120 -65x+24x=120

41x=120 -41x=120

We reduce both sides by 41 -41

41x41=12041 \frac{-41x}{-41}=\frac{120}{-41}

We find that x is equalx=12041 x=-\frac{120}{41}

Answer

12041 -\frac{120}{41}

Exercise #10

Solve for X:

24x+12x+38x15x=1 \frac{2}{4}x+\frac{1}{2}x+\frac{3}{8}x-\frac{1}{5}x=1

Video Solution

Step-by-Step Solution

To solve this equation, we will follow these steps:

  • Step 1: Identify the least common denominator (LCD) for the fractions 24x \frac{2}{4}x , 12x \frac{1}{2}x , 38x \frac{3}{8}x , and 15x \frac{1}{5}x .
  • Step 2: Convert each fraction to have the LCD as the denominator.
  • Step 3: Combine the fractions to form a single expression.
  • Step 4: Solve the resulting equation for x x .

Now, let's work through each step:

Step 1: The denominators are 4, 2, 8, and 5. The LCD of these numbers is 40.

Step 2: Convert each fraction:

24x=2×1040x=2040x \frac{2}{4}x = \frac{2 \times 10}{40}x = \frac{20}{40}x

12x=1×2040x=2040x \frac{1}{2}x = \frac{1 \times 20}{40}x = \frac{20}{40}x

38x=3×540x=1540x \frac{3}{8}x = \frac{3 \times 5}{40}x = \frac{15}{40}x

15x=1×840x=840x -\frac{1}{5}x = -\frac{1 \times 8}{40}x = -\frac{8}{40}x

Step 3: Combine all fractions:

2040x+2040x+1540x840x \frac{20}{40}x + \frac{20}{40}x + \frac{15}{40}x - \frac{8}{40}x

=20+20+15840x = \frac{20 + 20 + 15 - 8}{40}x

=4740x = \frac{47}{40}x

Step 4: Solve the equation 4740x=1 \frac{47}{40}x = 1 .

Multiply both sides by 4047 \frac{40}{47} to solve for x x :

x=1×4047 x = 1 \times \frac{40}{47}

x=4047 x = \frac{40}{47}

Therefore, the solution to the problem is x=4047 x = \frac{40}{47} .

Answer

4047 \frac{40}{47}

Exercise #11

Solve for X:

14x15x+23x25x=1 \frac{1}{4}x-\frac{1}{5}x+\frac{2}{3}x-\frac{2}{5}x=1

Video Solution

Step-by-Step Solution

To solve the given equation 14x15x+23x25x=1 \frac{1}{4}x - \frac{1}{5}x + \frac{2}{3}x - \frac{2}{5}x = 1 , follow these steps:

Step 1: Find a common denominator for the fractions involved. The denominators are 4, 5, 3, and again 5. The least common multiple (LCM) of these numbers is 60.

Step 2: Rewrite each fraction with the common denominator of 60:

  • 14x=1560x\frac{1}{4}x = \frac{15}{60}x
  • 15x=1260x-\frac{1}{5}x = -\frac{12}{60}x
  • 23x=4060x\frac{2}{3}x = \frac{40}{60}x
  • 25x=2460x-\frac{2}{5}x = -\frac{24}{60}x

Step 3: Combine the fractions:

1560x1260x+4060x2460x\frac{15}{60}x - \frac{12}{60}x + \frac{40}{60}x - \frac{24}{60}x

This simplifies to:

1512+402460x=1960x\frac{15 - 12 + 40 - 24}{60}x = \frac{19}{60}x

Step 4: Set up the equation:

1960x=1\frac{19}{60}x = 1

Step 5: Solve for x x by isolating it on one side of the equation. Multiply both sides by the reciprocal of 1960\frac{19}{60}, which is 6019\frac{60}{19}:

x=1×6019x = 1 \times \frac{60}{19}

x=6019x = \frac{60}{19}

Therefore, the solution to the problem is x=6019=157 x = \frac{60}{19} = \frac{15}{7} after simplifying the fraction.

Answer

157 \frac{15}{7}

Exercise #12

Solve for X:

23x+14x15x+12x=2 \frac{2}{3}x+\frac{1}{4}x-\frac{1}{5}x+\frac{1}{2}x=2

Video Solution

Step-by-Step Solution

To solve for x x in the equation 23x+14x15x+12x=2 \frac{2}{3}x+\frac{1}{4}x-\frac{1}{5}x+\frac{1}{2}x=2 , we will follow these steps:

Step 1: Combine the coefficients of x x by finding a common denominator.
- The denominators are 3, 4, 5, and 2. The least common multiple (LCM) of these is 60.
- Rewrite each term with a denominator of 60:
23x=4060x\frac{2}{3}x = \frac{40}{60}x, 14x=1560x\frac{1}{4}x = \frac{15}{60}x, 15x=1260x\frac{1}{5}x = \frac{12}{60}x, 12x=3060x\frac{1}{2}x = \frac{30}{60}x.

Step 2: Combine the fractions:
- Combine to get: 4060x+1560x1260x+3060x=7360x.\frac{40}{60}x + \frac{15}{60}x - \frac{12}{60}x + \frac{30}{60}x = \frac{73}{60}x.

Step 3: Set up the equation and solve for x x :
- The equation becomes 7360x=2\frac{73}{60}x = 2.
- Multiply both sides by 6073\frac{60}{73} to isolate x x :
x=2×6073 x = 2 \times \frac{60}{73} .

Therefore, x=12073 x = \frac{120}{73} .

Answer

12073 \frac{120}{73}