Supplementary angles sum up to 180 degrees T + S = 180 degrees, (5x-3) + (2x+1) = 180 7x - 2 = 180 7x = 180 + 2 7x = 182 x = 182/7 = 26 T = 5x-3 = 5*26-3 = 127 degrees, S = 2x+1 = 2*26+1 = 53 degrees.