Posted by Miley on Friday, December 27, 2013 at 9:30am.
A line has xintercept (5, 0) and is perpendicular to the line 2x + 8y = 10. Find the yintercept of the line.

Math  Reiny, Friday, December 27, 2013 at 10:27am
your given line of 2x + 8y = 10 has slope 2/8 or 1/4
so the slope of a perpendicular line is +4
its equation is y = 4x + b, but (5,0) lies on it, so
0 = 4(5) + b
b = 20
new equation: y = 4x  20
and the yintercept is 20, (since we have it in slope yintercept form)