The triangles are confusing please help

D. b=15 and a=7

Step-by-step explanation:

compare the left triangle to the right triangle by looking at the short sides

How do we get from 9 to 3?

setting an equation

9x = 3

divide both sides by 9

x = 3/9 simplified to 1/3

The scale factor is 1/3

so a is:

21 × 1/3 = 7

b is:

5 ÷ 1/3 = 15

y=−9/2x+10

step-by-step explanation:

let's solve for y.

0−9x−2y=−20

step 1: add 9x to both sides.

−9x−2y+9x=−20+9x

−2y=9x−20

step 2: divide both sides by -2.

−2y

−2

=

9x−20

−2

y=

−9

2

x+10

21.4 i did it already for s1

step-by-step explanation: