Bonsoir,
Développer et réduire l'expression B=x-(x-7)²+x²
= x -(x² -14x +49) +x²
= x - x² + 14x - 49 +x²
= 15x - 49
Factoriser C=9(x+3)+(2x-1)(x+3)
= (x+3)(9+2x-1)
= (x+3)(8+2x)
Factoriser D=81-4x²
= 9² - (2x)²
= (9+2x)(9-2x)
Factoriser E=(2x-7)²-3(2x-7)
= (2x-7)(2x-7 -3)
= (2x-7)(2x -10)
Factoriser F=16x²-8x+1
= (4x)² - 2×4x×1 + 1²
= (4x -1)²
Factoriser G=(x-6)²-16
= (x-6)² - 4²
= (x-6 +4)(x-6 -4)
= (x -2)(x -10)
Développer et réduire l'expression A=2(3x-7)+(x+1)²
= 6x - 14 + (x² + 2x + 1)
= 6x - 14 + x² + 2x + 1
= x² + 8x -13
Bonne soirée !! ^^
