Bonjour,
N=6 + (5x-2)(3-4x)
N = 6 + 15x - 20x² - 6 + 8x
N = - 20x² + 15x + 8x + 6 - 6
N = - 20x² + 23x
P=5y-(4y+3)(-2y-5)
P = 5y - (- 8y² - 20y - 6y - 15)
P = 5y + 8y² + 20y + 6y + 15
P = 8y² + 5y + 20y + 6y + 15
P = 8y² + 31y + 15
R=6(2z-1)(3-z)
R = (12z - 6) (3 - z)
R = 36z - 12z² - 18 + 6z
R = - 12z² + 36z + 6z - 18
R = - 12z² + 42z - 18.
