7×(1.4у+1.8)-27.6=10.1у

[tex]9.8y + 12.6 - 27.6 = 10.1y \\ - 15 = 0.3y \\ y = - \frac{15 \times 1}{3} = - 5[/tex]

9.8y+12.6-27.6=10.1y
0.3y=15
y=15:0.3
y=50