About Solving Proportions:

A proportion states that two ratios/rates are equal. We can check to see if we have a proportion by cross multiplying. When the cross products are equal, we know we have a proportion. We solve a proportion equation by cross multiplying and using our four-step method for solving equations.


Test Objectives
  • Demonstrate the ability to determine if two ratios/rates represent a proportion
  • Demonstrate the ability to solve a proportion equation
  • Demonstrate the ability to solve a proportion word problem
Solving Proportions Practice Test:

#1:

Instructions: Solve each equation.

a)

12 =   x
10x - 3

b)

 -7p = -3
p + 410

#2:

Instructions: Solve each equation.

a)

k + 8 = 5k + 6
  12    4

#3:

Instructions: Solve each equation.

a)

  4 =     12
r - 311r - 1

#4:

Instructions: Solve each equation.

a)

 y - 10 = -11
2y + 8 12

#5:

Instructions: Solve each equation.

a) If 7 gallons of gas cost $27.58, how much would it cost to fill a 40 gallon tank?


Written Solutions:

#1:

Solutions:

a) x = 18

b)

p = 12
67

#2:

Solutions:

a)

k = -5
 7

#3:

Solutions:

a) r = -1


#4:

Solutions:

a)

y = 16
17

#5:

Solutions:

a) It would cost $157.60 to fill a 40 gallon tank.