Solving Word Problems One-Step Equations Using Addition or Subtraction

To solve n + 23 = 65 you would...

• add 23 to both sides of the equation.

• add 65 to both sides of the equation.

• subtract 65 from both sides of the equation.

• subtract 23 from both sides of the equation.

Answer explanation

To solve n + 23 = 65, you would subtract 23 from both sides of the equation to isolate the variable n and find its value.

Which equation can be used to solve this problem:Tye is cooking muffins. The recipe calls for 7 cups of sugar. She has already put in 2 cups. How many more cups does she need?

• 7 + 2 = x

• x = 2 + 7

• 2(7) = x

• 2 + x = 7

There were 3 roses in the vase. Jessica cut some more roses from her flower garden. There are now 27 roses in the vase. How many roses did she cut?

• 24

• 30

• 42

Answer explanation

Jessica cut 24 roses from her flower garden to make the total number of roses in the vase 27 (27 - 3 initial roses = 24 roses cut). Therefore, she cut 24 roses.

Andrew has saved $55 toward the purchase of a Nintendo Switch. The Switch costs $145. Which equation represents the amount Andrew needs to save so he can buy the Switch?

• 55 + x = 145

• 145x = 55

• 55 - x = 145

• 145 (55) = x

Answer explanation

To find the value of x, we need to isolate x in the equation 55 + x = 145. By subtracting 55 from both sides, we get x = 90.

Tyrell has saved $62 to buy a new phone. How many more dollars must Tyrell save if the cost of the phone is $89? Let d be the number of dollars Tyrell must still save?

• 62 + d = 89

• 62d = 89

• d ÷ 89 = 62

• d - 62 = 89

Which equation can be used to solve this problem: Mike bought five pens for a total of $20. How much did each pen cost?

• 5 + x = 20

• x - 20 = 5

• x/5 = 20

• 5x = 20

Answer explanation

Choose 5x = 20 as the correct equation since Mike bought 5 pens for $20, and we need to find the cost per pen.

Which equation can be used to solve this problem: Each pair of socks costs $2.50. if Ella buys 6 pairs, how much does she pay (x)?

• 6x = 2.50

• 2.50 = 6x

• 6 = 2.50x

• 2.50(6) = x

Answer explanation

The correct equation is 2.50(6) = x because Ella buys 6 pairs of socks at $2.50 each, so the total cost is calculated by multiplying the cost per pair by the number of pairs.

Janeen's mother is 47. She is 26 years older than Janeen. Which equation can be used to find Janeen's age j?

• j + 26 = 47

• 26j = 47

• j - 26 = 47

• 47j = 26

x - 62 = 123
How should you show your work to isolate the variable and solve the equation?

• Add 62 to each side. 

• Subtract 62 from each side.

• Multiply each side by 62.

• Add 123 to each side.

What is the correct step to solve for the variable?
15 = m - 5

• add 15 to both sides

• add 5 to both sides

• subtract 15 from both sides

• subtract 5 from both sides