Setting Up Equations to Solve for Unknowns in Math

Sarah has 5 apples and buys some more. If she has a total of 12 apples now, how many did she buy? Define the variable for the number of apples bought.

• 10

• 3

• 7

• 5

Tom has twice as many marbles as Jerry. If Jerry has x marbles and together they have 30 marbles, how many marbles does each have? Set up an equation to find x.

• Jerry has 10 marbles and Tom has 20 marbles.

• Jerry has 12 marbles and Tom has 18 marbles.

• Jerry has 15 marbles and Tom has 15 marbles.

• Jerry has 5 marbles and Tom has 25 marbles.

A book costs $15. If you buy y books, how much will you spend in total? Write an equation to represent the total cost.

• total_cost = 15 / y

• total_cost = 15 + y

• total_cost = 15 - y

• total_cost = 15 * y

Lily has 20 stickers. She gives away some stickers to her friends and now has z stickers left. If she gave away 8 stickers, how can you express this situation with an equation?

• z = 20 + 8

• z = 8 - 20

• z = 20 - z

• z = 20 - 8

A box can hold 24 toys. If you have x boxes, how many toys can you store in total? Write an equation to find the total number of toys.

• total_toys = 24 - x

• total_toys = 12 + x

• total_toys = 24 * x

• total_toys = x - 24

In a classroom, there are 3 times as many girls as boys. If there are b boys, how can you express the total number of students in the classroom? Set up an equation.

• 3b

• 4b

• 2b

• 5b

A farmer has 50 apples and sells some. If he has a left with a total of a apples, how many did he sell? Write an equation to find the number of apples sold.

• 50 + a

• 50 / a

• 50 - a

• a - 50

Emma has 10 more than twice the number of candies that Mia has. If Mia has c candies, how can you express the number of candies Emma has? Set up an equation.

• 2c - 10

• 2c + 10

• 3c - 5

• c + 10

A pizza is cut into 8 slices. If you eat s slices, how many slices are left? Write an equation to represent the remaining slices.

• s - 8

• s * 8

• 8 - s

• 8 + s

A toy costs $10. If you want to buy p toys, how much money do you need in total? Write an equation to find the total cost.

• total_cost = p + 10

• total_cost = 10 * p

• total_cost = 10 - p

• total_cost = 10 / p