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 ! :)
