Odpowiedź:
-2x+8y-(6x-7y)=-2x+8y-6x+7y=-8x+15y=-8•1+15•(-2)=
=-8-30=-38
(3u-6v)+(6v-5)=3u-6v+6v-5=3u-5=3•3-5=9-5=4
(8u+3v)-(2u+5v)=8u+3v-2u-5v=6u-2v=6•3-2•(-1)=18+2=20
(-a-4b)+(5b-a)=-a-4b+5b-a=b=-4
(7a-b)-(4a-2b)=7a-b-4a+2b=3a+b=3•4+(-4)=12-4=8
