bonjour
* = fois
2 x = 2 * x
4 x + 5 = 4 * x + 5
4 ( x - 3 ) ( x + 8 ) = 4 * ( x * x + x * 8 - 3 * x - 3 * 8 )
3 x - 2 ( 5 x - 15 ) = 3 * x - 2 * ( 5 * x - 15 )
9 x² = 9 * x * x
7 - 2 x = 7 - 2 * x
2 ( 3 x - 2 ) = 2 * ( 3 * x - 2 * - 2 )
x ( x + 2 ) - 4 x = x * x + x * 2 - 4 * x
4 x² - 4 x ( 4 - x ) = 4 * x * x - 4 * x ( 4 - x )
- 3 x² + 5 x - 4 = - 3 * x * x + 5 *x - 4
tu remplaces x par 2
exemple A = 2 x = 2 * 2 = 4
B = 4 x + 5 = 4 * 2 + 5 = 8 + 5 = 13
bonne soirée
