Answer :
[tex]5(wx-v)=9(x+v)\\
5wx-5v=9x+9v\\
5wx-9x=14v\\
x(5w-9)=14v\\
x=\frac{14v}{5w-9}[/tex]
expand the brackets first
5(wx-v) = 9(x + v)
5wx - 5v = 9x + 9v
Get all x's on one side and everything on on the other side
9x - 5wx = 9v + 5v
factorise out the x
x(9-5w) = 14v
then divide by 9-5w
x = 14v/(9-5w)
5(wx-v) = 9(x + v)
5wx - 5v = 9x + 9v
Get all x's on one side and everything on on the other side
9x - 5wx = 9v + 5v
factorise out the x
x(9-5w) = 14v
then divide by 9-5w
x = 14v/(9-5w)