How do you find the slope and y intercept of #x+y=7#?

Question

3790 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-01-11T21:46:55

slope = - 1
y-intercept = 7

one form of the equation of a straight line is y = mx + c where m =slope and c is the y-intercept.

rearranging the equation x + y = 7 into this form gives :

y = - x + 7

comparing the 2 equations we see that m = - 1 and c = 7

here is the graph of y = - x +7

graph{-x+7 [-20, 20, -10, 10]}

Answer 2 · 2016-01-11T21:48:38

Slope #=-1#
Y-intercept #=7#

Start with the equation #x+y=7#.
Subtract #x# from both sides to get #y=-x+7#.

The slope is the coefficient of the #x# term. In this case, it is assumed to be #-1# because #-x=-1x#.

The y-intercept is the value of #y# when #x=0#. After substituting #0# for #x#, we get #y=-0+7#. This equals #y=7#, so the y-intercept is #7#.