Question

Tìm x biết: 3.(5x - 4) - 7.(2x - 3) = 17

Answer 1

=> (15x - 12) - (14x - 21) = 17

=> 15x - 12 - 14x + 21 = 17

=> (15x-14x) - (12 - 21) = 17

=> x - (-9) = 17

=> x = 17 + (-9)

=> x = -8

Answer 2

=> (15x - 12) - (14x - 21) = 17

=> 15x - 12 - 14x + 21 = 17

=> (15x-14x) - (12 - 21) = 17

=> x - (-9) = 17

=> x = 17 + (-9)

=>x = 8

vậy x=8