Verified answer

[(5х + 178) * 15 + 90] : 45 = 63

(5х + 178) * 15 + 90 = 63 * 45

(5х + 178) * 15 + 90 = 2835

(5х + 178) * 15 = 2835 - 90

(5х + 178) * 15 = 2745

5х + 178 = 2745 : 15

5х + 178 = 183

5х = 183 - 178

5х = 5

х = 5 : 5

х = 1