Examples with solutions for Equations with Absolute Values: Solving the problem

Exercise #1

x=7 \left|x\right|=7

Step-by-Step Solution

The equation is x=7 \left|x\right|=7 , which means that the absolute value of x x is 7. Therefore, x x could be 7 or -7. Thus, the solutions are x=7 x=7 and x=7 x=-7 .

Answer

x=7,x=7 x=-7, x=7

Exercise #2

x=3 \left|x\right|=3

Step-by-Step Solution

The equation is x=3 \left|x\right|=3 , which implies that x x can be 3 or -3. Hence, the solutions are x=3 x=3 and x=3 x=-3 .

Answer

Answers a + c

Exercise #3

x=4 \left|x\right|=4

Step-by-Step Solution

The equation is x=4 \left|x\right|=4 . This means that the value of x x can be either 4 or -4. Thus, the solutions are x=4 x=4 and x=4 x=-4 .

Answer

Answers a + c

Exercise #4

x=6 \left|x\right|=6

Step-by-Step Solution

The equation is x=6 \left|x\right|=6 , so x x could be 6 or -6. Therefore, the solutions are x=6 x=6 and x=6 x=-6 .

Answer

Answers b + c

Exercise #5

3x=15 \left|-3x\right|=15

Step-by-Step Solution

To solve 3x=15 \left|-3x\right|=15 , we consider both potential cases stemming from the absolute value:

1) 3x=15-3x=15:

Divide both sides by 3-3 to get x=5x=-5.

2) 3x=15-3x=-15:

Divide both sides by 3-3 to get x=5x=5.

Thus, the solutions are x=5 x=-5 and x=5 x=5.

Answer

x=5 x=-5 , x=5 x=5

Exercise #6

2x=16 \left|-2x\right|=16

Step-by-Step Solution

To solve the equation 2x=16 \left|-2x\right|=16 , we consider the definition of absolute value:

1. The expression inside the absolute value can be either positive or negative, but its absolute value is always positive.

2. Therefore, we set up two equations to solve:

2x=16 -2x = 16 and 2x=16 -2x = -16

3. Solving the first equation:

2x=16 -2x = 16

4. Divide both sides by -2:

x=8 x = -8

5. Solving the second equation:

2x=16 -2x = -16

6. Divide both sides by -2:

x=8 x = 8

7. Therefore, the solution is:

x=8 x=-8 , x=8 x=8

Answer

x=8 x=-8 , x=8 x=8

Exercise #7

3x=21 \left|3x\right|=21

Step-by-Step Solution

To solve the equation 3x=21 \left|3x\right|=21 , we consider the definition of absolute value:

1. The expression inside the absolute value can be either positive or negative, but its absolute value is always positive.

2. Therefore, we set up two equations to solve:

3x=21 3x = 21 and 3x=21 3x = -21

3. Solving the first equation:

3x=21 3x = 21

4. Divide both sides by 3:

x=7 x = 7

5. Solving the second equation:

3x=21 3x = -21

6. Divide both sides by 3:

x=7 x = -7

7. Therefore, the solution is:

x=7 x=-7 , x=7 x=7

Answer

x=7 x=-7 , x=7 x=7

Exercise #8

4x=12 \left|-4x\right|=12

Step-by-Step Solution

To solve the equation 4x=12 \left|-4x\right|=12 , we consider the definition of absolute value:

1. The expression inside the absolute value can be either positive or negative, but its absolute value is always positive.

2. Therefore, we set up two equations to solve:

4x=12 -4x = 12 and 4x=12 -4x = -12

3. Solving the first equation:

4x=12 -4x = 12

4. Divide both sides by -4:

x=3 x = -3

5. Solving the second equation:

4x=12 -4x = -12

6. Divide both sides by -4:

x=3 x = 3

7. Therefore, the solution is:

x=3 x=-3 , x=3 x=3

Answer

x=3 x=-3 , x=3 x=3

Exercise #9

x=15 -\left|x\right|=15

Step-by-Step Solution

Let's solve the equation x=15 -\left|x\right|=15 . Since the expression inside the absolute value can be either positive or negative, we consider two scenarios:

1. x=15 -x = 15 : This implies x=15 x = -15 .

2. (x)=15 -(-x) = 15 : This simplifies to x=15 x = 15 .

Thus, the solutions are x=15 x = -15 and x=15 x = 15 .

Answer

x=15 x=-15 , x=15 x=15

Exercise #10

x=8 -\left|x\right|=8

Step-by-Step Solution

Let's solve the equation x=8 -\left|x\right|=8 . The expression inside the absolute value can take two forms:

1. x=8 -x = 8 : This gives x=8 x = -8 .

2. (x)=8 -(-x) = 8 : This simplifies to x=8 x = 8 .

Therefore, the solutions are x=8 x = -8 and x=8 x = 8 .

Answer

x=8 x=-8 , x=8 x=8

Exercise #11

y3=7 \left| y - 3 \right| = 7

Step-by-Step Solution

To solve y3=7 \left| y - 3 \right| = 7 , we need to consider the two possible cases for the absolute value equation.

1. y3=7 y - 3 = 7 leads to y=10 y = 10

2. y3=7 y - 3 = -7 leads to y=4 y = -4

Thus, the solutions are y=10 y = 10 and y=4 y = -4 .

Answer

y=10 y = 10 ,y=4 y = -4

Exercise #12

z+4=12 \left| z + 4 \right| = 12

Step-by-Step Solution

To solve z+4=12 \left| z + 4 \right| = 12 , consider the two cases:

1. z+4=12 z + 4 = 12 gives z=8 z = 8

2. z+4=12 z + 4 = -12 gives z=16 z = -16

Thus, the solutions are z=8 z = 8 and z=16 z = -16 .

Answer

z=16 z = -16 , z=8 z = 8

Exercise #13

a2=6 \left| a - 2 \right| = 6

Step-by-Step Solution

To solve a2=6 \left| a - 2 \right| = 6 , consider the cases:

1. a2=6 a - 2 = 6 leads to a=8 a = 8

2. a2=6 a - 2 = -6 leads to a=4 a = -4

Thus, the solutions are a=8 a = 8 and a=4 a = -4 .

Answer

a=8 a = 8 , a=4 a = -4

Exercise #14

6x12=6 \left|6x-12\right|=6

Video Solution

Step-by-Step Solution

To solve this exercise, we need to note that the left side is in absolute value.

Absolute value checks the distance of a number from zero, meaning its solution is always positive.

 

Therefore, we have two possibilities, either the numbers inside will be positive or negative,

In other words, we check two options, in one what's inside the absolute value is positive and in the second it's negative.

 

6x-12=6

6x=18

x=3

This is the first solution

 

-(6x-12)=6
-6x+12=6
-6x=6-12
-6x=-6
6x=6
x=1

And this is the second solution,

So we found two solutions,

x=1, x=3

And that's the solution!

Answer

x=1 x=1 , x=3 x=3

Exercise #15

2x+1=9 \left| 2x + 1 \right| = 9

Step-by-Step Solution

To solve 2x+1=9 \left| 2x + 1 \right| = 9 , we consider two cases:

1. 2x+1=9 2x + 1 = 9 implies 2x=8x=4 2x = 8 \to x = 4

2. 2x+1=9 2x + 1 = -9 implies 2x=10x=5 2x = -10 \to x = -5

Thus, the solutions are x=4 x = 4 and x=5 x = -5 .

Answer

x=4 x = 4 , x=5 x = -5

Exercise #16

2x4=10 2|x - 4| = 10

Step-by-Step Solution

To solve the equation 2x4=10 2|x - 4| = 10 , divide both sides by 2. This gives x4=5|x - 4| = 5 .

The absolute value equation x4=5|x - 4| = 5 implies that x4=5x - 4 = 5 or x4=5x - 4 = -5 . Solving these equations:

1. x4=5x - 4 = 5 gives x=9x = 9 .

2. x4=5x - 4 = -5 gives x=1x = -1 .

Thus, the solutions are x=9x = 9 and x=1x = -1 .

Answer

Answers b + c

Exercise #17

3x+2=18 3|x + 2| = 18

Step-by-Step Solution

To solve 3x+2=18 3|x + 2| = 18 , first divide by 3 to get x+2=6|x + 2| = 6 .

This absolute value equation means x+2=6x + 2 = 6 or x+2=6x + 2 = -6 . Solving these:

1. x+2=6x + 2 = 6 leads to x=4x = 4 .

2. x+2=6x + 2 = -6 leads to x=8x = -8 .

Therefore, the solutions are x=4x = 4 and x=8x = -8 .

Answer

Answers b + c

Exercise #18

2x4=8 \left|2x - 4\right|=8

Step-by-Step Solution

To solve 2x4=8 \left|2x - 4\right|=8 , we split it into two cases based on the nature of absolute values:

1) 2x4=82x - 4=8:

Add 44 to both sides: 2x=122x=12.

Divide both sides by 22 to get x=6x=6.

2) 2x4=82x - 4=-8:

Add 44 to both sides: 2x=42x=-4.

Divide both sides by 22 to get x=2x=-2.

So, the solutions are x=2 x=-2 and x=6 x=6.

Answer

x=2 x=-2 , x=6 x=6

Exercise #19

4x+1=9 \left|4x+1\right|=9

Step-by-Step Solution

To solve 4x+1=9 \left|4x+1\right|=9 , split into two scenarios:

1) 4x+1=94x+1=9:

Subtract 11 from both sides to get 4x=84x=8.

Divide both sides by 44 to find x=2x=2.

2) 4x+1=94x+1=-9:

Subtract 11 from both sides to get 4x=104x=-10.

Divide both sides by 44 to find x=2.5x=-2.5.

Thus, x=2 x=2 and x=2.5 x=-2.5 are solutions.

Answer

x=2 x=2 , x=2.5 x=-2.5

Exercise #20

5x+2=13 \left|-5x + 2\right|=13

Step-by-Step Solution

To solve 5x+2=13 \left|-5x + 2\right|=13 , address the two absolute value cases:

1) 5x+2=13-5x + 2=13:

Subtract 22 from both sides to get 5x=11-5x=11.

Divide by 5-5 to find x=2.2x=-2.2.

2) 5x+2=13-5x + 2=-13:

Subtract 22 from both sides to get 5x=15-5x=-15.

Divide by 5-5 for x=3x=3.

The solutions are x=3 x=3 and x=2.2 x=-2.2.

Answer

x=3 x=3 , x=2.2 x=-2.2