Odpowiedź :
a) 4x(y-2)-2(5x+xy)=4xy-8x-10x-2xy=2xy-18x
b) x(x-1)+2x(4+x)-3(4x-2x)=
x²-x+8x+2x²-6x=3x²+x
c) x(y-xy)-y(2x-xy)=xy-x²y-2xy+xy²=-xy-x²y+xy²
d) 5(x+y)-9y-4(y-x)+x=5x+5y-9y-4y+4x+x=10x-8y
e) 10a-(6a+1)+7(6-a)=
10a-6a-1+42-7a=-3a+41
b) x(x-1)+2x(4+x)-3(4x-2x)=
x²-x+8x+2x²-6x=3x²+x
c) x(y-xy)-y(2x-xy)=xy-x²y-2xy+xy²=-xy-x²y+xy²
d) 5(x+y)-9y-4(y-x)+x=5x+5y-9y-4y+4x+x=10x-8y
e) 10a-(6a+1)+7(6-a)=
10a-6a-1+42-7a=-3a+41