[tex] A= \frac{1}{2} h (x+y) [/tex]
we have to solve for x , solving for x means , we have to isolate x one one side , by shifting all other variables to other side
So
[tex] A= \frac{1}{2} h (x+y) [/tex]
Multiply both sides by 2
2A = h(x+y)
Divide both sides by h
2A/h = x+y
Subtract y from both sides
[tex] \frac{2A}{h} -y =x [/tex]
or
[tex] x=\frac{2A}{h} -y [/tex]
