Bonjour !
K = 3(2x - 6) - (3 - 5x)
K = 3*2x - 6*3 - 3 + 5x
K = 6x - 18 - 3 + 5x
K = 11x - 21
L = (5 - 2y) - (-3y + 7)
L = 5 - 2y + 3y - 7
L = y - 2
M = 4(6 + z) + (z - 3)(2 - z)
M = 4*6 + 4*z + z*2 - 3*2 - z*z - 3*(-z)
M = 24 + 4z + 2z - 6 - z² + 3z
M = -z² + 9z + 18
N = (2t - 5)(3t + 2) - (t² + 6)
N = 2t*3t - 5*3t + 2t*2 - 5*2 - t² - 6
N = 6t² - 15t + 4t - 10 - t² - 6
N = 5t² - 11t - 16
J'espère t'avoir aidé. Bon courage !
