Dm de maths important merci d avance

Bonjour,

A=

-6x²  -4+21

= -6x² +17

B=

18/30-20/30+15/30

= 13/30

C=

-3/5(* 2/3 - 3/3)

= -3/5 * -1/3

=3 /15 = 1/5

D=

(5/4) / (3/3+2/3)

= (5/4) / (5/3)

= 5/4 * 3/5 = 15/20  = 3/5

I =

x-3 -4+2x

= 3x -12

J=

6x² -15x  

K =

x -x² +3-3x

= -x² -2x +3

L=

10x² -2x +15x -3

= 10x²  +13x -3

a)

2x=-2

x= -2/2 =

x= -1

b)

-3x= 1-4

-3x = -3

x= -3/-3 = 3/3

x= 1

c)

+1-2 = 3x +2x

-1 = 5x

x= -1/5