Question 898714
Graph it. It's a parabola.

Then look for points of intersection.

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{{{drawing(300,300,-16,4,-100,300,grid(1),circle(2,4,0.12),graph(300,300,-16,4,-100,300,x^2,30-13x))}}}

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There are two points of intersection. 
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{{{drawing(300,300,-2,5,-2,5,grid(1),circle(2,4,0.12),graph(300,300,-2,5,-2,5,x^2,30-13x))}}}
(2,4)
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{{{drawing(300,300,-20,-10,-20,400,grid(1),circle(2,4,0.12),graph(300,300,-20,-10,-20,420,x^2,30-13x))}}}
Looks like {{{x=-15}}} is the other intersection point. 
use either function to calculate the y value.
{{{y=x^2=(-15)^2=225}}}
(-15,225)