Répondre :
A = (x+4)(x+2)
A = x² + 4x + 2x + 8
A = x² + 6x + 8
B = (x+2)(0,5+x)
B = 0,5x + 1 + x² + 2x
B = x² + 2,5x + 1
A = x² + 4x + 2x + 8
A = x² + 6x + 8
B = (x+2)(0,5+x)
B = 0,5x + 1 + x² + 2x
B = x² + 2,5x + 1
a) ( x + 4 ) ( x + 2 )
= x* x + x * 2 + 4 * x + 4 * 2
= x^2 + 2x + 4x + 8
= x^2 + 6x + 8
b) ( x + 2 ) ( 0,5 + x )
= x* 0,5 + x * x + 2 * 0,5 + 2 * x
= 0,5x + x^2 + 1 + 2x
= x^2 + 2,5x + 1
= x* x + x * 2 + 4 * x + 4 * 2
= x^2 + 2x + 4x + 8
= x^2 + 6x + 8
b) ( x + 2 ) ( 0,5 + x )
= x* 0,5 + x * x + 2 * 0,5 + 2 * x
= 0,5x + x^2 + 1 + 2x
= x^2 + 2,5x + 1