Bonjour,
Factoriser les expressions:
3(x+1)+(x+1)³-(x²+4)(x+1)= (x+1)[3+(x+1)²-(x²+4)]= (x+1)(3+x²+2x+1-x²-4)= 2x(x+1)
14(2a-3)³+(2A-b)(3-2a)^4= 14(2a-3)³+(2a-b)(2a-3)^4
= (2a-3)³[ 14+(2a-b)(2a-3) ]
= (2a-3)³[14+(4a²-2ab-6a+3b)]
= (2a-3)³(14+4a²-2ab-6a+3b)
(3-x²)(2x-7)-(2-x²)(14-4x)+6x-21= (2x-7)(3-x²)+[ 2(2-x²)(7-2x)]+3(2x-7)
= (2x-7)(3-x²+4-2x²+3)= (2x-7)(-3x²+10)
= - (2x-7)(3x²-10)
121x-66√x+9= (11√x-3) (11√x-3)= (11√x-3)² identité remarquable.
16(x-3)²-144(x+2)²= 4²(x-3)(x+4)-(x+3)²(x-3)²- 12²(x+2)² IR
= [ 4(x-3) - 12(x+2)] [ 4(x-3)+12(x+2) ]
= (4x-12-12x-24)(4x-12+12x+24)
= (-8x-36)(16x+12)= 4*4(-2x-9)(4x+3)
= - 16(2x+9)(4x+3)
