Решите уравнение 2.7+3y=9(y-2.1) 0.3(8-3y)=3.2-0.8(y-7)
2.7+3у=9(у-2.1)
2.7+3у=9у-18.9
3у-9у=-18.9-2.7
-6у=-21.6
у=3.6
0.3(8-3у)=3.2-0.8(у-7)
2.4-0.9у=3.2-0.8у+5.6
2.4-0.9у=8.8-0.8у
-0.9у=0.8у=8.8-2.4
-0.1у=6.4
у=-64