For the 1st one RSV = TSU (Vertical angles are congruent)
9x - 28 = 6x + 2
3x = 30
x = 10
RSV = 62
The 2nd one
Alternate exterior angles are congruent
Thus
10x + 5 = 125
10x = 120
x = 12
The 3rd one
When triangles are similar their sides are promotional and their angles are congruent
thus
A and D
The 4th one
Find Angle A
Angle A + 3Angle A + 76 = 180
4 Angle A = 104
Angle A = 26