Answer:
2x = 80
2x - 15 = 65
y = 80
3x - 20 = 100
Explanation:
The first thing to do is find x from 2x and 3x - 20. Any other first step won't work.
These two angles are supplementary. Supplementary angles always total 180 degrees.
3x - 20 + 2x = 180 Combine like terms
5x -20 = 180 Add 20 to both sides.
5x - 20 + 20 = 180 + 20 Combine left side
5x = 180 + 20 Combine right side
5x = 200 Divide by 5
5x/5 = 200/5
x = 40
Givens
The lines are parallel
3x - 20 and 2x are supplementary
Alternate angles are equal so y = 2x
Solution
2x = 2*40 = 80
y = 80
3x - 20 = 3*40 - 20 = 120 - 20 = 100
2x - 15 = 2*40 - 15 = 80 - 15 = 65