Solve this and explain for full points:

x=30, y=90

Step-by-step explanation:

y+x  and y-x are supplementary angles.  They must add to 180 degrees

y+x+y-x = 180

Combine like terms

2y = 180

Divide by 2

2y/2 = 180/2

y= 90

y+x  and 2x are supplementary angles.  They must add to 180 degrees

y+x+2x = 180

y+3x =180

We know y =90

90+3x=180

Subtract 90 from each side

90-90 +3x = 180-90

3x= 90

Divide by 3

3x/3 = 90/3

x = 30

a is the right answer

13cm

step-by-step explanation:

(apex)