Answer:
Sum of two interior angles=exterior angle




Done!
how much is for electricity?
Squares : Triangles
3 : 12
Divide both sides by 3.
The simplest ratio is
1 : 4
9(2w−y)=21w−9y
First you multiply the numbers in the parenthesis by 9

subtract. 21w-18w=3w

add. -9y+9y=0

divide.

Final answer is 0.