3х+2х-(7х+10х)=5х-7х-10х=-12х
2у+4у-(у+13у)=6у-14у=-8у
4х+8у-(3у-17+х)=4х+8у-3у+17-х=3х+5у+17
х-(у-7)-(13х-6х)=х-у+7-7х=-6х-у+7
8,4а+(1,7-6,4b-2,7b)=8,4a+1,7-9,1b
2a+3/5b-8+(2 2/5b-1,5a)=
2a+3/5b-8+2 2/5b-1,5a=0,5a+3b-8
5,5b-(c+7,5b+20)-2,3c=
5,5b-c-7,5b-20-2,3c=-2b-3,3c-20