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
Proportions:
#1:
Instructions: Solve each equation.
a)
12 | = | x |
10 | x - 3 |
b)
-7p | = | -3 |
p + 4 | 10 |
#2:
Instructions: Solve each equation.
a)
k + 8 | = | 5k + 6 |
12 | 4 |
#3:
Instructions: Solve each equation.
a)
4 | = | 12 |
r - 3 | 11r - 1 |
#4:
Instructions: Solve each equation.
a)
y - 10 | = | -11 |
2y + 8 | 12 |
#5:
Instructions: Solve each word problem.
a) If 7 gallons of gas cost $27.58, how much would it cost to fill a 40 gallon tank?
Written Solutions:
Solution:
a) x = 18
b)
p | = | 12 |
67 |
Solution:
a)
k | = | -5 |
7 |
Solution:
a) r = -1
Solution:
a)
y | = | 16 |
17 |
Solution:
a) It would cost $157.60 to fill a 40 gallon tank.