Question

72÷8+42÷3-(9×a+2)=12 ; (285-81)÷102+(a×45-70)×20=400

Answer 1

9 + 14 - ( 9a + 2 ) = 12
13 - 9a+ 2 = 12
15 - 9a = 12
9a = 3
a = 3/9 = 1/3

204 ÷ 102 + ( 45 a - 70 ) x 20 = 400
2 + 900 a - 1400 = 400
2 + 900a = 1800
900 a = 1800 - 2
900a = 1798
a = 899 / 450