Please help me!, s'il vous plait aidez moi!​

Réponse:

1) E=(x-3)(5x+2)-(x-3)²

=5x²+2x-15x-6-(x²-2×x×3+3²)

=5x²-13x-6-x²+6x-9

=4x²-7x-15

2) E=(x-3)(5x+2)-(x-3)²

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

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

3) E=(x-3)(4x+5)=0

x-3=0 ou 4x+5=0

x=3. ou 4x=-5

x=3. ou. x= -5/4