(3х+2)(3х-4)=(2х+3)(3х-1)+(3х+1)(х-4)

(3x + 2)(3x - 4) = (2x + 3)(3x - 1) + (3x + 1)(x - 4)

9x² - 12x + 6x - 8 = 6x² - 2x + 9x - 3 + 3x² - 12x + x - 4

9x² - 6x - 8 = 9x² - 4x - 7

-6x + 4x = 7 + 8

-2x = 1

x = -0,5.

(3х+2)(3х-4)=(2х+3)(3х-1)+(3х+1)(х-4); 9x^{2}-12х+6х-8=6x^{2}-2х+9х-3+3х-12х+х-4; 9x^{2}+6х-8=9x^{2}+8х-7; 6х-8=8х-7; 6х-8х=-7=8; -2х=1; х=-0,5