Explanation:
question 15
For y to be parallel to z the sum of given angles must be equal to 180°
3x + 7 + 10x - 22 = 180° add like terms
13x - 15 = 180 add 15 to both sides
13x = 195 divide both sides by 13
x = 15
question 16
If y is parallel to z then the given angles are alternate exterior and has same measurement
11x - 3 = 4x + 39
11x - 4x = 39 + 3
7x = 42 divide both sides by 7
x = 6