1. 3х+18=2х-6 3х-2х=-6-18 х=-24
2. 9х-27=5х+25 9х-5х=25+27 4х=52 х=52:4=13
3. 4-2у=у-5 -2у-у=-5-4 -3у=-9 3у=9 у=9:3=3
4.-3х+4=3х-8 -3х-3х=-8-4 -6х=-12 6х=12 х=12:6=2
5. 2-4у+3у-3=2у-4-4у -4у+3у-2у+4у=-4-2+3 у=-3
6.10-15х+3х-6=7х+56-2х-1 -15х+3х-7х+2х=56-1-10+6 -17х=51 17х=-51 х=-51:17=-3
Вроде так