Solving Proportions

Solving Proportions

Notice on #1: 7(3)=21 and 12(3)=36

1st step: Cross multiply 3(2.5)

2nd Step: Cross multiply 5(15)

Last step: Do they equal each other? Yes: it is proportional.

No: Non-proportional

Multiple Choice

 $\frac{1}{4}\ ;\ \ \frac{8}{32}$  Is this ratio proportional?

• YES

• NO

Multiple Select

 $\frac{x}{8}=\frac{15}{24}$    1st: Multiply x(24), 2nd: Multipliy 8(15), 3rd: Solve for x.

• x=5

• x=120

• x=24

Multiple Select

6.   $\frac{40}{y}=\frac{4}{5}$  

• y=10

• y=50

• y=4

Multiple Select

7.   $\frac{6}{2}=\frac{n}{14}$  

• n=40

• n=41

• n=42

Multiple Select

8.   $\frac{4}{10}=\frac{32}{k}$  

• k=80

• k=320

• k=40

Multiple Select

9.   $\frac{m}{3}=\frac{126}{18}$  

• m=21

• m=20

• m=378

Multiple Select

10.   $\frac{15}{21}=\frac{10}{e}$  

• e=210

• e=14

• e=15

Multiple Select

11.   $\frac{9}{6}=\frac{c}{10}$  

• c=6

• c=15

• c=14

Multiple Select

12.   $\frac{6}{4}=\frac{21}{r}$  

• r=14

• r=12

• r=6

How do you think we could solve for x?

Set up your ratios

• 1st step: Blue ratio

• 2nd step: Red ratio

• 3rd step: Cross multiply

• 4th step: Solve for x

Set up your ratios

• 1st step: ounces ratio

• 2nd step: Cost ($) ratio

• 3rd step: Cross multiply

• 4th step: Solve for x

Multiple Choice

• m=80

• m=81

• m=1

Multiple Choice

• m=80

• m=81

• m=1