Verified answer

Salut !

A= 7(a+3b)

= 7a+21b.

B= x(x-5)

= x^2 -5x.

C= 7a(4b+2-5c)

= 28ab+14a-35ac.

D= 2a(3b-8)+8b(9a+7)

= 6ab-16a + 72ab + 56b

= 78ab - 16a + 56b.

E= 9(x-9) + 7x( 5 + x)

= 9x - 81 + 35x + 7x^2

= 7x^2 + 44x - 81.

Bonne journée !

Bonjour,

A = 7(a + 3b)

A = ( 7 * a ) + ( 7 * 3b )

A = 7a + 21b

B = x(x - 5)

B = ( x * x ) - ( x * 5 )

B = x² - 5x

C = 7a(4b + 2 - 5c)

C = ( 7a * 4b ) + ( 7a * 2 ) - ( 7a * 5c )

C = 28ab + 14a - 35ac

D = 2a(3b - 8) + 8b( 9a + 7)

D = ( 2a * 3b ) - ( 2a * 8 ) + ( 8b * 9a ) + ( 8b * 7 )

D = 6ab - 16a + 72ab + 56b

D = 78ab + 16a + 56b

E = 9(x - 9) + 7x(5 + x)

E = ( 9 * x ) - ( 9 * 9 ) + ( 7x * 5 ) + ( 7x * x )

E = 9x - 81 + 35x + 7x²

E = 44x - 81 + 7x²

Bonne journée ! :)