Solving Proportions with One Variable

Are the two ratios proportional?

• YES

• NO

For the pair of similar figures, find the length of each side marked with a variable.

• 13.4 cm

• 15 cm

• 12.5 cm

• 7.2 m

For the pair of similar figures, find the length of each side marked with a variable.

• x = 7.2 cm; y = 13.4 cm

• x = 12cm; y = 15 cm

• x = 12.5 cm; y = 9.6 cm

• x = 15 cm; y = 12 cm

Hint:  Draw a picture of the scenario and label the diagrams to assist in solving the real world problem.

• 9.8 in

• 1.8 in

• 9.3 in

• 10.4 in

Solve the proportion.

• k=5

• k=3.3333333

• k=60

• k=90

To solve proportions, you must...

• Multiply the numerators with the numerators

• Cross multiply

• Set equations equal

• Multiply by the denominator

The variable, k, is being divided by 11. How should you show your work to isolate the variable?

• Divide both sides by 11

• Multiply both sides by 11.

• Add 11 to both sides.

• Subtract 11 to both sides.

• x = 1

• x = 2

• x = 1/2

• x = 3/2

Solve the proportion shown:

Solve the proportion shown:

• r = 22

• r =11

• r = -22

• r = 101