Using the equations for trapezoids:
VW = 1/2(RS + UT)
3x+5 = 1/2(2x+15 + 6x-37)
Do inside parenthesis first:
3x+5 = 1/2(8x -22)
Multiply inside the parenthesis by 1/2:
3x+5 = 4x-11
Add 11 to both sides:
3x +16 = 4x
Subtract 3x from both sides:
16 = x
Now you know x = 16 solve for RS:
2(16) + 15 = 32 +15 = 47
RS = 47
