Odpowiedź:
zadanie 1
15+(y+x)=15+y+x
3x-(8a+b)=3x-8a-b
-(y+2)+(a-b)= -y-2+a-b
zadanie 2
3(x+8y)=3x+24y
-2(x+2)+(2x-8)= -2x-4+2x-8= -12
5x-(4x+11)=5x-4x-11=x-11
zadanie 3
(y-2)(y+3)=y²+3y-2y-6=y²+y-6
(3y+2)²=(3y+2)(3y+2)=9y²+6y+6y+4=9y²+12y+4
zadanie 4
2x(5-x)-(6x²+3)=10x-2x²-6x²-3=10x-8x²-3=
=10•(-3)-8•(-3)²-3= -30-8•9-3= -33-72= -105
