Question

-11.2+4(2.1+q) = -0.8solve and can you explain how to solve? I am confused 

Answer 1

Given
-11.2+4(2.1+q) = -0.8

Take -11.2 to the right hand side of the equation (sign will change when we move it to the other side)
∴ 4(2.1+q) = -0.8 + 11.2

Simply both sides
∴ 4*2.1 + 4*q = 11.2-0.8
∴ 8.4 + 4q = 10.4

Take 8.4 to the right hand side
∴ 4q = 10.4 - 8.4
∴ 4q = 2
∴ q = 2/4
∴ q = 1/2 = 0.5

Answer 2

$-11.2+4(2.1+q) = -0.8\\ -11.2+8.4+4q=-0.8\\ 4q=2\\ q=\frac{2}{4}=\frac{1}{2}$