Is ( +6)/2-14=34 supposed to be (square + 6)/2-14=34 ?
If so, then:
(square + 6)/2 - 14 = 34
add 14 to both sides
(square + 6)/2 - 14 + 14 = 34 + 14
simplify
(square + 6)/2 = 48
multiply both sides by 2
2*(square + 6)/2 = 2 * 48
simplify
square + 6 = 96
subtract 6 from both sides
square + 6 - 6 = 96 - 6
simplify
square = 90
(square) - (7x5)+6 = 21
multiply the 7 and 5 together
(square) - (35)+6 = 21
combine the 35 and 6 together
(keep in mind the 35 is - and the 6 is +
(square) - 29 = 21
add 29 to both sides
(square) - 29 + 29 = 21 + 29
square = 50