Respuesta :

w=4x+9y
-9y=-w+4x
9y=w-4x
y=(w-4x)/9

Hope this helps :)
To solve for y.

w = 4x + 9y,       

take over 4x to the other side of the equation and it becomes -4x

w - 4x = 9y     

9y = w - 4x

Divide both sides by 9

9y/9  = (w - 4x)/9

y = (w - 4x)/9

I hope this explains it.