Ответ:

Пошаговое объяснение:

1)

(х+3)(х-2) - (х+4)(х-1) = 3х

(х²-2х+3х-6) - (х²-х+4х-4) = 3х

(х²+х-6) - (х²+3х-4) = 3х

х² + х - 6 - х² - 3х + 4 = 3х

х - 3х - 6 + 4 = 3х

-2х - 2 = 3х

-2х - 3х = 2

-5х = 2

х = 2 : (-5)

х = -0,4

2)

15х² - (3х-2)(5х+4) = 16

15х² - (15х²+12х-10х-8) = 16

15х² - (15х²+2х-8) = 16

15х² - 15х² - 2х + 8 = 16

-2х + 8 = 16

-2х = 16 - 8

-2х = 8

х = 8 : (-2)

х = -4

1)

(х+4)(х-2) - (х+8)(х-4) =

(х²-2х+4х-8) - (х²-4х+8х-32) =

(х²+2х-8) - (х²+4х-32) =

х² + 2х - 8 - х² - 4х + 32 =

-2х + 24

х = -3,5

-2*(-3,5) + 24 = 7 + 24 = 31

2)

(2х-3)(х-1) + (х+3)(3х+1) =

(2х²-2х-3х+3) + (3х²+х+9х+3) =

(2х²-5х+3) + (3х²+10х+3) =

2х² - 5х + 3 + 3х² + 10х + 3 =

5х² + 5х + 6

х = -3/5

5*(-3/5)² + 5*(-3/5) + 6 =

5*9/25 - 15/5 + 6 =

45/25 - 3 + 6 =

9/5 + 3 = 1. 4/5 + 3 = 4. 4/5