20)
11x - 2 = 75 ( corresponding angles are congruent)
Add 2 to both-side of the equation
11x = 75 + 2
11x = 77
Divide both-side by 11
x = 7
21)
8x -4 = 60 (alternate angles are congruent)
Add 4 to both-side of the equation
8x = 60 + 4
8x = 64
Divide both-side of the equation by 8
x = 8
22)
x + 139 = 132 (alternate angles are congruent)
Subtract 139 from both-side of the equation.
x = 132 - 139
x= -7
23)
-1+14x = 12x + 17 (alternate angles are congruent)
Collect like term.
14x - 12x = 17 + 1
2x = 18
Divide both-side by 2
x=9
24)
23x - 5 = 21x + 5 ( corresponding angles are congruent)
Collect like terms.
23x - 21x = 5 + 5
2x = 10
Divide both-side by 2
x = 5