dévélopper et réduire H=2(x-1)-5x ; I=(x-3)(7-4x)

H = 2 (x - 1) - 5x
H = 2x - 2 - 5x
H = 2x - 5x - 2
H = - 3x - 2

I = (x - 3) (7 - 4x)
I = 7x - 4x² - 21 + 12x
I = - 4x² + 7x + 12x - 21
I = - 4x² + 19x - 21

h:2(x₋1)₋5
2x₋2₋5
2x₋7
I:(x₋3)(7₋4x)
7x₋4x²₋21₊12x
₋4x²₊19x₋21