0,9-3y= -7,2-12y reshite ples

Question

0,9-3y= -7,2-12y reshite ples

Answer 1

0.9+7.2=-12y+3y
8.1=-9y
y=-0.9
вот и все

Answer 2

9y=-8.1
y=-8.1/9=-81/10*1/9=!-0.1!