How do you find the slope of 2x+8y=92x+8y=9?

1 Answer
Sally
Dec 11, 2014

In the general form of a line y=mx+by=mx+b, mm represents the slope of the line and bb the y-intercept. Here, we have the line 2x+8y=92x+8y=9...we want it in the form y=mx+by=mx+b so we can get our mm (the slope) directly.

To do this, we simply solve 2x+8y=92x+8y=9 for y with some algebra:

2x+8y=92x+8y=9
-Take 2x2x to the left hand side of the equation by subtracting it from both sides
8y=9-2x=-2x+98y=9−2x=−2x+9
-Divide by 8 on both sides of the equation to get y alone
y=-2/8x+9/8=-1/4x+9/8y=−28x+98=−14x+98

And there we have the line y=-1/4x+9/8y=−14x+98, with m=slope=-1/4m=slope=−14

Related questions
See all questions in Equations of Parallel Lines
Impact of this question
8655 views around the world
You can reuse this answer
Creative Commons License