Question

[(5xa+178)x15+90]:45=63

Answer 1

[(5×a+178)×15+90]:45=63
[(5a+178)×15+90]=63×45
[(5a+178)×15+90]=2835
(5a+178)×15=2835-90
(5a+178)×15=2745
5a+178=2745:15
5a+178=183
5a=5
a=5:5
a=1

Answer 2

[(5 x a + 178 ) x 15 + 90 ] : 45 = 63
(5 x a + 178 ) x 15 + 90 = 63 x 45
(5 x a + 178 ) x 15 + 90 = 2 835
(5 x a + 178 ) x 15 = 2 835 - 90
(5 x a + 178 ) x 15 = 2 745
5 x a + 178 = 2 745 : 15
5 x a + 178 = 183
5 x a = 183 - 178
5 x a = 5
a = 5 : 5
a = 1

Succes !!!!