SOLUTION: If the slope of a line through the origin is 2, and the the line through (b,-2) and (a,5) is parallel to that line, what is the value of a?

Algebra ->  Linear-equations -> SOLUTION: If the slope of a line through the origin is 2, and the the line through (b,-2) and (a,5) is parallel to that line, what is the value of a?      Log On


   

Question 717334: If the slope of a line through the origin is 2, and the the line through (b,-2) and (a,5) is parallel to that line, what is the value of a?
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
The line through the origin, having no other x or y intercept but slope of 2, is y=2x.

The slope of the line defined by points given is %285-%28-2%29%29%2F%28a-b%29=2, equated because that line is given as parallel to y=2x. Solve for a, and find that highlight%28a=7%2F2%2Bb%29.