Verified answer

Bonjour;

12x = 9-4

12x = 5

x=5/12

-8 -2 = 7x-5x

-10 = 2x

x= -10/2

x= -5

1)

(2x-3) ( 5x+1 -x+3)

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

2)

identité remarquable

( 4x-9)(4x+9)