How do you find the slope and intercept of #3x+7=0#?

2 Answers
Jun 14, 2018

Answer:

The slope is 3 and the intercept is 7.

Explanation:

First off the equation should read #3x + 7 = y# just easier to make sense of.

The values you are looking for are in the formula:

The slope is a ratio of how much #y# increases based on how much #x# increases, it's usually calculated based on the "rise over run" it looks like this:

#"rise (increase in y)"/"run (increase in x)"#

In the case of this formula, #y# increases 3 units for every unit #x# increase. I'll put a graph in and you can pick any 2 points on the line and find the amount #x# and #y# increases (say #y=0;x=5# and #y=15;x=10# then in amount y increases is 15 units while x increases by 5) then the slope is calculated like this:

#15/5=3# This gives you the 3 in the equation #color(red)(3)x+7=y#

The intercept is the value of #y# when #x# equals 0. If you substitute #x=0# into the equation you can see that the only thing left to that gives a value is 7.

#cancel(3(0))+7=y -> y=7# When #x=0# So 7 is your intercept.

graph{3x+7 [-12.3, 16.17, -2.06, 12.18]}

Jun 14, 2018

Answer:

#"see explanation"#

Explanation:

#"subtract 7 from both sides and divide by 3 gives"#

#x=-7/3#

#"this is the equation of a vertical line parallel to the y-axis"#
#"passing through all points with an x-coordinate of "-7/3#

#"the slope is therefore undefined"#

#"the x-intercept "=-7/3" there is no y-intercept"#
graph{(y-1000x-2333)=0 [-10, 10, -5, 5]}