Question

Розв’яжіть рівняння (3х + 4)(4х – 3) – 5 = (2х + 5)(6х – 7).

Answer 1

(3х + 4)(4х – 3) – 5 = (2х + 5)(6х – 7)

12х^2 - 9x + 16x - 12 - 5 = 12x^2 - 14x + 30x - 35

- 9x + 16x - 12 - 5 = -14x + 30x - 35

7x - 16x = 17 - 35

-9x = -18

x = 2

Ответ: 2

Answer 2

$\sf~(3x+4)\cdot(4x-3)-5=(2x+5)\cdot(6x-7)~;\\3x\cdot~4x-3x\cdot3+4\cdot4x-4\cdot3-5=2x\cdot6x-2x\cdot7+5\cdot6x-5\cdot7~;\\12x^2-9x+16x-12-5=12x^2-14x+30x-35~;\\-9x+16x-12-5=-14x+30x-35~;\\7x-17=16x-35~;\\7x-16x=-35+17~;\\-9x=-18~;\\x=-18:(-9)~;\\\boxed{\bf x=2} ~.$