SOLUTION: If one point on a line is (6,-5) and the line's slope is -9, find the y-intercept.

Algebra ->  Functions -> SOLUTION: If one point on a line is (6,-5) and the line's slope is -9, find the y-intercept.      Log On


   

Question 1112166: If one point on a line is (6,-5) and the line's slope is -9, find the y-intercept.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

The given point is (6,-5) which means x = 6 and y = -5 pair up together.
The slope is -9, so m = -9

Plug those three values (m = -9, x = 6, y = -5) into the slope intercept formula y+=+mx%2Bb then solve for b. Recall that b of y = mx+b is the y intercept

y+=+mx%2Bb

y+=+-9x%2Bb Replace m with -9

-5+=+-9%286%29%2Bb Plug in (x,y) = (6,-5). In other words, replace x with 6 and replace y with -5

-5+=+-54%2Bb Multiply

-5%2B54+=+-54%2Bb%2B54 Add 54 to both sides

49+=+b Simplify

b+=+49 Flip the equation

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Answer: The y intercept is 49 which is represented by the ordered pair (0,49)

This is where the graph crosses the y axis.