# analytic geometry … 2 problems

1st problem : find the equation of the straight line having slope $m$ passing through the point $(a, 0)$. What are the coordinates of the point of intersection of this line with the y-axis?
2nd problem : find an equation of the line passing through the point $(1, 5)$ with a negative slope and forms with the coordinates axis a triangle with area $10$ sq. units. Please I want answers with steps.

Thank you!

• I believe almost identical questions have been asked here $n + 1$ times. – glebovg Nov 9 '12 at 5:32
• It is much easier to google: equation of a line. – glebovg Nov 9 '12 at 5:33
• So, what do you know about equations of lines? Hard to answer the questions in a helpful way without knowing that. – Gerry Myerson Nov 9 '12 at 5:35
• i have only 15 years old and i have try to solve them more than 5 times ! – ibrahim Nov 9 '12 at 5:36
OP has gone to ground, but I find the second question shows some imagination, so I'll outline an answer. A line through $(1,5)$ has equation $$y-5=m(x-1)$$ for some $m$. When $x=0$, $y=5-m$; when $y=0$, $x=1-(5/m)$. The condition on the area of the triangle leads to $$(1/2)(5-m)(1-(5/m))=10$$ Clearing fractions, this is $$(5-m)(m-5)=20m$$ and from here it should be routine to solve.