SOLUTION: Find an equation for the linear function g(x) which is perpendicular to the line 5 x - 4 y = 8 and intersects the line 5 x - 4 y = 8 at x = 20.

Algebra ->  Linear-equations -> SOLUTION: Find an equation for the linear function g(x) which is perpendicular to the line 5 x - 4 y = 8 and intersects the line 5 x - 4 y = 8 at x = 20.       Log On


   

Question 901779: Find an equation for the linear function g(x) which is perpendicular to the line 5 x - 4 y = 8 and intersects the line 5 x - 4 y = 8 at x = 20.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
The point of intersection is supposed to be x=20, and 5%2A20-4y=8,
5%2A5-y=2
25-2=y
y=23
The point (20,23).

The line perpendicular to that given line is 4x%2B5y=c, which choice uses knowledge of the standard form in which the equation is written. Substituting the found point of intersection (the expected point of intersection) will give the value for c:
4%2A20%2B5%2A23=c
highlight_green%28c=135%29.

Now, the line being found, perpendicular to the given line at (20,23) is
4x%2B5y=135.
Solve this for y, and THAT is your desired function, g%28x%29.

5y=-4x%2B135
highlight%28g%28x%29=y=-%284%2F5%29x%2B27%29