exo 1:
1) A= (2x-3)²+(4x+7) (2x-3)
A= (2x)²-2×2x×3+3²+4x×2x+4x×(-3) +7×2x+7×(-3)
A= 4x²-12x+9+8x²-12x+14x-21
A= 12x²-10x-12
2) A= (2x-3) ²+(4x+7) (2x-3)
A= (2x-3) (2x-3) +(4x+7) (2x-3)
A= (2x-3) [ (2x-3) +(4x+7) ]
A= (2x-3) [2x-3+4x+7]
A= (2x-3) [ 6x+4]
exo2:
1)B= 4x(5x-2)+25x²-4
B= 4x×5x+4x×(-2)+25x²-4
B= 20x²-8x+25x²-4
B= 45x²-8x-42)
B=25x²-4
B= (5x)²-2²
B= (5x+2)(5x-2)
exo 3:
3) Q= (4-x) ²-4
Q= 4²-2×4×x+x²-4
Q= 16-8x+x²-4
Q= x²-8x+12
j'arrive pas à faire le reste.
