( x ÷ 2 - 15) × 3 + 11 = 50
( x ÷ 2 - 15) × 3 = 50 - 11 = 39
x ÷ 2 - 15 = 39 ÷ 3 = 13
x ÷ 2 = 13 + 15 = 28
x = 28 × 2
x = 56