SOLUTION: Please help: Determine the equation of the line that has a slope of 4 and passes through the point (2,8). Write the equation in slope intercept form

Algebra ->  Linear-equations -> SOLUTION: Please help: Determine the equation of the line that has a slope of 4 and passes through the point (2,8). Write the equation in slope intercept form      Log On


   

Question 51248: Please help: Determine the equation of the line that has a slope of 4 and passes through the point (2,8). Write the equation in slope intercept form
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Write the equation in slope-intercept form:
y+=+mx%2Bb
You are given the slope, m = 4, so you can write:
y+=+4x%2Bb Now you need to find the value of b, the y-intercept. This is easily done because you were also given a point (2, 8) through which the line passes.
So you substitute the (x, y) of the given popint (2, 8) into the equation y+=+4x%2Bb and solve for b.
8+=+4%282%29+%2B+b Simplify.
8+=+8+%2B+b Subtract 8 from both sides of the equation.
0+=+b So b = 0. Now you can write the final equation of the line whose slope is 4 and which passes through the point (2, 8).
y+=+4x
Just out of curiosity, let's see what that looks like on a graph:
graph%28300%2C200%2C-5%2C5%2C-5%2C10%2C4x%29