Should that be (square + 6)/2 - 14 = 34 ?
add 14 to both sides
(square + 6)/2 = 48
multiply both sides by 2
square + 6 = 96
subtract 6 from both sides
square = 90
square -(7*5) +6 = 21
square -(35) +6 = 21
square -29 = 21
add 29 to both sides
square = 50