Examples with solutions for All Operations in the Order of Operations: Using variables

Exercise #1

Solve the equation and find Y:

20×y+8×27=14 20\times y+8\times2-7=14

Video Solution

Step-by-Step Solution

We begin by placing parentheses around the two multiplication exercises:

(20×y)+(8×2)7=14 (20\times y)+(8\times2)-7=14

We then solve the exercises within the parentheses:

20y+167=14 20y+16-7=14

We simplify:

20y+9=14 20y+9=14

We move the sections:

20y=149 20y=14-9

20y=5 20y=5

We divide by 20:

y=520 y=\frac{5}{20}

y=55×4 y=\frac{5}{5\times4}

We simplify:

y=14 y=\frac{1}{4}

Answer

14 \frac{1}{4}

Exercise #2

Solve the exercise below given that:X=4 X=4

(X+4)(3+X) (X+4)(3+X)

Video Solution

Step-by-Step Solution

We start by substituting the value of X X

(4+4)(3+4) (4+4)(3+4)

First, we perform the calculation in parentheses

(8)(7) (8)(7)

After this, we solve the parentheses and can continue with the simple multiplication exercise.

7×8=56 7\times 8=56

Answer

56

Exercise #3

How much is x equal to?

2542 ⁣:x+18×2 ⁣:4=23 -25-42\colon x+18\times2\colon4=-23

Video Solution

Step-by-Step Solution

We begin by placing the multiplication exercise inside of parentheses:

2542 ⁣:x+(18×2) ⁣:4=23 -25-42\colon x+(18\times2)\colon4=-23

2542 ⁣:x+36 ⁣:4=23 -25-42\colon x+36\colon4=-23

We will then place the division exercise inside of parentheses:

2542 ⁣:x+(36 ⁣:4)=23 -25-42\colon x+(36\colon4)=-23

2542 ⁣:x+9=23 -25-42\colon x+9=-23

Next we rearrange the exercise in order to simplify it:

25+942 ⁣:x=23 -25+9-42\colon x=-23

(25+9)42 ⁣:x=23 (-25+9)-42\colon x=-23

We then solve the exercise inside of the parenthesis and obtain the following:

1642 ⁣:x=23 -16-42\colon x=-23

We rearrange the fractions and obtain the following:

42 ⁣:x=23+16 -42\colon x=-23+16

42 ⁣:x=7 -42\colon x=-7

We multiply by x and obtain the following:

42=7x -42=-7x

Lastly we divide by negative 7:

x=427=6 x=\frac{-42}{-7}=6

Answer

6

Exercise #4

92x×224 ⁣:4=64 92-x\times2-24\colon4=64

Calculate X.

Video Solution

Step-by-Step Solution

First, we solve the multiplication and division exercises, we will put them in parentheses to avoid confusion:

92(x×2)(24 ⁣:4)=64 92-(x\times2)-(24\colon4)=64

922x6=64 92-2x-6=64

Reduce:

862x=64 86-2x=64

Move the sides:

2x=6486 -2x=64-86

2x=22 -2x=-22

Divide by negative 2:

x=222 x=\frac{-22}{-2}

x=11 x=11

Answer

11

Exercise #5

How much is Xequal to?

(3217)×4×9 ⁣:350 ⁣:x=170 (32-17)\times4\times9\colon3-50\colon x=170

Video Solution

Step-by-Step Solution

To solve forx x in the equation (3217)×4×9 ⁣:350 ⁣:x=170 (32 - 17) \times 4 \times 9 \colon 3 - 50 \colon x = 170 , we will follow the order of operations: parentheses, exponents, multiplication and division (from left to right), and addition and subtraction (from left to right).

Step 1: Evaluate the Parentheses
First, solve the expression inside the parentheses: 3217=15 32 - 17 = 15 .

Substitute back into the equation:
15×4×9 ⁣:350 ⁣:x=170 15 \times 4 \times 9 \colon 3 - 50 \colon x = 170 .

Step 2: Perform Multiplication and Division
Continue with the multiplication and division from left to right.

  • First, multiply15 15 and 4 4 :
    15×4=60 15 \times 4 = 60

  • Next, multiply 60 60 by 9 9 :
    60×9=540 60 \times 9 = 540

  • Then, divide 540 540 by3 3 :
    540 ⁣:3=180 540 \colon 3 = 180

  • Now, subtract 50x \frac{50}{x} from 180 180 :
    18050x=170 180 - \frac{50}{x} = 170

Step 3: Isolate x x
We isolatex x by adding 50x \frac{50}{x} to both sides of the equation:
180=170+50x 180 = 170 + \frac{50}{x}

Subtract 170 from both sides:
180170=50x 180 - 170 = \frac{50}{x}

This simplifies to:
10=50x 10 = \frac{50}{x}

Step 4: Solve forx x
To find x x , solve the equation10x=50 10x = 50 which is derived from multiplying both sides by x x :
x=5010 x = \frac{50}{10}

The value of x x is:
x=5 x = 5

The final answer is 5 5 .

Answer

5

Exercise #6

What is the number that should replace y?

2312×(5)+y ⁣:7+[214]=107 23-12\times(-5)+y\colon7+\lbrack21-4\rbrack=107

Video Solution

Step-by-Step Solution

We begin by solving the multiplication exercise:

12×(5)=60 12\times(-5)=-60

and subsequently the exercises within brackets:

214=17 21-4=17

We obtain the following:

23(60)+y:7+17=107 23-(-60)+y:7+17=107

Keep in mind that a negative times a negative becomes a positive:

23+60+y:7+17=107 23+60+y:7+17=107

Next we simplify and add:

23+60=83 23+60=83

83+17=100 83+17=100

We obtain the following calculation:

100+y:7=107 100+y:7=107

We then rearrange the sections:

y:7=107100 y:7=107-100

y7=7 \frac{y}{7}=7

Lastly we multiply by 7:

y=7×7=49 y=7\times7=49

Answer

49