Question

{[(13x5xa-194)x5-3]x19+3x4}:25=18:9

Answer 1

{ [( 13 x 5 x a - 194 ) x 5 - 3] x 19 + 3 x 4} : 25 = 18 : 9

{ [ ( 65 x a - 194 ) x 5 - 3 ] x 19 + 12 } : 25 = 2

[ ( 65 x a - 194 ) x 5 - 3 ] x 19 + 12 = 2 x 25

[ ( 65 x a - 194 ) x 5 - 3 ] x 19 = 50 - 12

( 65 x a - 194 ) x 5 - 3 = 38 : 19

( 65 x a - 194 ) x 5 - 3 = 2

( 65 x a - 194 ) x 5 = 2 + 3

( 65 x a - 194 ) x 5 = 5

65 x a - 194 = 5 : 5

65 x a = 1 + 194

65 x a = 195

a = 195 : 65

a = 3