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Bonjour,
Développer
A=5(2a+3)+ a= 10a+15+a= 11a+15
C=x(2-7x)-x= 2x-7x²-x= - 7x²+x
B=6(4-b)+b= 24-6b+b= - 5b+24
D=4x(3x+1)-2x²= 12x²+4x-2x²= 10x²+4x
bonjour
A = 5(2a + 3) + a
= 5*2a + 5*3 + a distributivité
= 10a + 15 + a on associe les termes en a
= 10a + a + 15 [ 10a + 1a = '10 + 1)a = 11a ]
= 11a + 15
B = 6(4 - b) + b
= 6*4 - 6*b + b
= 24 - 6b + b
= 24 - 5b
C = x(2 - 7x) - x
= x *2 - x*7x - x
= 2x - 7x² - x
= -7x² + 2x - x
= -7x² + x
D = 4x(3x + 1) - 2x²
= 4x*3x + 4x*1 - 2x²
= 12x² + 4x - 2x²
= 12x² - 2x² + 4x
= 10x² + 4x