a) 3(x+y-z) = 3x+3y-3z
b) (x+y-4)6 = 6x+6y-24
c) 2(x-y-z) = 2x-2y-2z
d) (a-b+c)7 = 7a-7b+7c
e) x(x+y-z) = x²+xy-xz
f)y(b+x-y) = by+xy-y²
g) 8(2x-5y+4z) = 16x-40y+32z
h) -4(15a+13b-c) = -60a-52b+4c
i) 3x(17x+15y-21) = 51x²+45xy-63x
j)-5y(5-y+5y) = -25y+5y²-25y²=-25y-20y²
k) 4a(-2a-3+a) = -8a²-12a+4a²=-4a²-12a
l) -0,5m(-2m+1-4) = m²-0,5m+2m = m²+1,5m