Explications étape par étape:

ex4

a. x(8+3) = 11x

b. x(11-19) = -8x

c. x(2 - 15 + 7) = -6x

d. x (0,5 - 1,2 + 1) = 0,3x

e. a(5 - 7) +b(-3 + 10) = -2a + 7b

f. x²(6 - 12 - 1) + x(-7 + 17) = 7x² + 10x

ex5

a. (2x × 5x) + (2x × -3) + 9x =

10x² - 6x + 9x = 10x² + 3x

b. (-4 × x) + (-4 ×2) - 7x + 8 =

-4x - 8 - 7x + 8 = -11x

c. (3x² × 2) + (3x² × -x) + 2x³ - 5x² =

6x² - 3x³ + 2x³ - 5x² = -x³ + x²