Question 353212
It's your y-intercept, graph it.
(0,25)
Another point would be 
{{{x=-2}}} and {{{y=25+15(-2)=-5}}}
(-2,-5)
Plot both the points then connect them with a line.
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It's a very steep curve so mind the x and y scales used in creating the graph. They may be misleading.
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{{{drawing(300,300,-10,10,-40,40,circle(0,25,0.4),circle(-2,-5,0.4),graph(300,300,-10,10,-40,40,25+15x))}}}
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{{{drawing(300,300,-10,10,-10,10,circle(0,25,0.4),circle(-2,-5,0.4),graph(300,300,-10,10,-10,10,25+15x))}}}
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If I had made them equal lengths, it wouldn't have been as interesting.
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