Question

Graph 3x-4y=12 using the slope and y-intercept.

How do I do this?

Answer 1

First isolate y on the left side of the equation.

Answer 2

So we have it in standard form

Answer 3

Sorry, math is one of my weakest subjects.
I don't really understand it at all.

Answer 4

Well the standard form is y=mx+b where m is the slope and b is the y interecept, so if we get it in that form we can graph it the way the question asks.

To get y by itself on the left, start by subtracting 3x from both sides so you get:
-4y=-3x+12

can you think of what we should do next?

Answer 5

The slope would be -3 and the y-intercept is 12 if I remember correctly.

Answer 6

Well we havent gotten y all by itself just yet, i was asking what we could do next in order to do that

Answer 7

Subtract the -3x

Answer 8

We did that and got -4y=-3x+12

How would we get rid of the -4 in front of the y?

Answer 9

Divide.

Answer 10

Yep, and what do you get?

Answer 11

y=\[ 3(-x+4) \over4\]

Answer 12

Just divide each one by -4

y=3/4x-3

Answer 13

So whats the slope and the y intercept?

Answer 14

Slope would be 3/4 and the y-intercept would be 3

Answer 15

y intercept would be -3, dont forget negatives

Answer 16

Right.

Answer 17

So you would plot a point at the y intercept (0, -3) and then use rise over run to find the next point and draw a straight line through them

Answer 18

3/4 would be up 3 right 4

Answer 19

Alright, thanks. I don't know why I can't get these.

Answer 20

You're welcome. Just practice with different ones and you'll get the hang of it.

Answer 21

I'll remember that. :)