1-Développer 0,5x X (10-x) = 5x - 0,5x²
2.2^9x2^5x(2^5)^4)x2^-3 = 2^14x2^20x2^-3 = 2^31
3. (3x+2)² - (3x+2) (5x-3) = 9x² + 12x + 4 - 15x² + 9x - 10x + 6 = -6x² + 11x + 10
4.Résoudre 5x+3 = 9x - 13 => -4x = -16 => x = 4
5.2x > -8 => x > - 4
6.
(2x+4)² = 4x² + 16x + 16
(5x-3)² = 25x² - 30x + 9
(4x + 3 ) (4x - 3) = 16x² - 9
c'est de la pure technique, refais les ....