А)2,136/(1,9-x)=7,12 б)4,2*(0,8+у)=8,82
а) 7.12 ( 1.9-X)=2.136
13.528-7.12X=2.136
-7.12= -11.392
X=1.6
Б) 4.2 (0.8+y)=8.82
3.36+4.2y=8.82
4.2y=5.46
y=1.3