Bonjour,
5(x-3) + 7(2x+5)
= (5x - 15) + ( 14x + 35)
= 5x - 15 + 14x + 35
= 19x + 20
(5x-5) (2x+3)
= 5x * 2x + 5x * 3 - 5 * 2x - 2 * 3
= 10x² + 15x - 10x - 6
= 10x² + 5x - 6
(4x+9)²
= (4x)² + 2 * 4x * 9 + 9²
= 16x² + 72x + 81
(2x-4)²
= (2x)² - 2 * 2x * 4 + 4²
= 4x² - 16x + 16
(5x-1)(5x+1)
= (5x)² - 1²
= 25x² - 1
Bonne continuation,
Courage en cette période compliquée,
Lucas.
