<span>(Y-3)^2 = 4y -12 <=> Y^2 - 6Y + 9 = 4y - 12 <=> 4y = Y^2 - 6Y + 21 <=> y = (Y^2 - 6Y + 21)/4. Solving the equation for y means that we have to express y relative to the other quantities in the equation.</span>
I got 2 but this could be wrong. Hope this helps ;D
X+60 + 70 = 180 (straight line)
x+130=180
x= 180 -130
x=50