Aidez moi s'il vous plaît :((

1)A=(5x+2)²-(3x-1)(5x+2)
A=25x²+20x+4-(15x²+6x-5x-2)
A=25x²+20x+4-15x²-6x+5x+2
A=10x²+19x+6

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

3) (0+2)²-(0-1)(0+2)
4-2
2

(7.5+2)²-(4.5-1)(7.5+2)
56.25+30+4-(33.75+9-7.5-2)
56.25+30+4-33.75-9+7.5+2
57
 
4) (5x+2)(2x+1)=0
5x+2=0  ou  2x+1=0
5x=-2    ou  2x=-1
x=-0.4  ou  x=-0.5

bonjour

A = 25 x² + 20 x +4 - ( 15 x² + 6 x - 5 x - 2)
A = 25 x² + 20 x + 4 - 15 x² - 6 x + 5 x + 2
A = 10 x² + 19 x + 6

2/ A = ( 5 x + 2) ( 5 x + 2 - 3 x + 1)
    A = ( 5 x + 2) ( 2 x + 3)

3/pour x = 0 
A = 2 * 3 = 6

pour x = - 3/2

a = ( - 15/2 + 2) ( - 6/2 + 3)
A = ( - 15/2 + 4/2) ( - 6/2 + 6/2)
A = ( - 11/2 ) ( 0) = 0

4/ A = 0

soit 5 x +2 = 0
       5 x = - 2 et x = - 2/5

soit 2 x +3 = 0
       2 x = - 3
et x = - 3/2