Sagot :
bonjour
2 x ( 3 x + 6 ) = 6 x² + 12 x
7 ( 2 x - 6 ) = 14 x - 42
( 6 x + 5 ) ( 2 x + 3 ) = 12 x² + 12 x + 10 x + 15 = 12 x² + 22 x + 15
( 7 x - 8 ) ( 2 x + 3 ) = 14 x² + 21 x - 16 x - 24 = 14 x² + 5 x - 24
( 2 x + 3 ) ( 5 y - 4 ) = 10 xy - 8 x + 15 y - 12
a = je ne le comprends pas
b 6 x - 12 = 6 ( x - 2 )
c) 35 x² - 40 x = 5 x ( 7 x - 8 )
Hello,
2x(3x + 6) = 2x * 3x + 2 * 6 = 6x² + 12
7(2x - 6) = 7 * 2x + 7 * -6 = 14x - 42
Il faut développer de la façon suivante :
(a + b)(c + d) = a * c + a * d + b * c + b * d
(6x + 5)(2x + 3) = 6x * 2x + 6x * 3 + 5 * 2x + 5 * 3 = .......
(7x - 8)(2x + 3) = 7x * 2x + 7x * 3 - 8 * 2x - 8 * 3 = .......
(2x + 3)(5y - 4) = 2x * 5y + 2x * -4 + 3 * 5y + 3 * -4 = .......
2x² + 2xy = 2x * x + 2x * y = 2x(x + y)
6x - 12 = 6 * x - 6 * 2 = 6(x - 2)
35x² - 40x = 5x * 7x - 5x * 8 = 5x(7x - 8)