equation help?

Question

help with equations..
Its for finding the y intercept of the graph equation:
2x+6y= -24

and this ones also for finding the y intercept of the graph equation:
y= -2 x+5

please explain step by step wht to do

Answer 1

I'm sorry, I misinterpreted the previous version of this question.

Rearrange to isolate y term: 6y = -24 - 2x
Divide by coefficient of y: y = -4 - x/3

Slope = -1/3
y-intercept = -4

Next one:
This is already in y=mx+b form, so the y-intercept is b, which is 5.

Answer 2

You may remember from Algebra class what slope/y-intercept form is. In case you don't, its written as ...

y = mx + b

where m = the slope (rise/run) and b = y-intercept.

the 2nd equation you listed is already in this form. So the m would be the number in front of the x and the y-intercept would be the number being added after the x. In this case, the y-intercept would be 5.

For the first equation, you have two choices. First, you can get y isolated on one side of the equal sign so its in the slope/y-intercept form. I am going to assume you can do that and show you the 2nd option.

When you are finding the y intercept of the graph, you are really answering the following question: "What is the value of y when x = 0." Remember, all points on the y axis have a value of 0 for x. To answer this question, you can take the equation and put in o for x, and then solve for y. In this case, you would have ...

2 (0) + 6y = -24 2 times 0 is 0, so you would now have...

0 + 6y = -24 there is no need to add 0, so drop it ...

6y = -24 I'll bet you can answer this one in your head!!

I am going to leave the final answer to you, but I will warn you -- becareful of that negative sign... it can make the difference between a right and a wrong answer.

Good luck with the rest of your homework!!!