Bonsoir,
. Factoriser ces expressions :
A=36-25x²
(6-5x) (6+5x)
B=100+60x+9x²
(3x +10)²
C=b²-10b²+25
= (b-5)²
E=(2-x)²+(2-x)(9-x)
= (2-x) ( 2-x +9-x)
= (2-x) ( -2x +1)
2. Développer les expressions littérales suivantes :
A=(2x-5)²
= 4x² -20x +25
B=(5x-3)(5x+3)
= 25x² - 9
C=(-3x+5)²
= 25 - 30x + 9x²
D=(-6x+9)²
= 36x² - 108x +81
Bonsoir,
Factoriser:
A=36-25x²= (6-5x)(6+5x) = -(5x-6)(5x+6)
B= 100+60x+9x²= (3x+10)²
C= b²-10b²+25= -9b²+25= (-3b+5)(3b+5)= -(3b-5)(3b+5)
E=(2-x)²+(2-x)(9-x)= (2-x)(2-x+9-x)= (2-x)(-2x+11)= (x-2)(2x-11)
Développer:
A=(2x-5)²= 4x²-10x-10x+25= 4x²-20x+25
B=(5x-3)(5x+3)= 25x²-15x+15x-9= 25x²-9
C=(-3x+5)²= 9x²-15x-15x+25= 9x²-30x+25
D=(-6x+9)²= 36x²-54x-54x+81= 36x²-108x+81