Question

4x[(4xa-72):4-20]-64=20

Answer 1

4x[(4xa-72):4-20]-64=20
4x[(4xa-72):4-20]=20 +64
4x[(4xa-72):4-20] = 84
(4xa-72):4-20 = 84 :4
(4xa-72):4-20 = 21
(4xa-72):4 = 21 +20
(4xa-72):4 = 41
4xa-72 = 41 x 4
4xa-72 = 164
4xa = 164 +72
4xa = 236
a = 236 :4
a = 59