Question

Write the equation in slope-intercept form.
5x - y =7
and
2x + 5y= 15

Then tell me how you do it?

Answer 1

Do you know what slope intercept form looks like?

Answer 2

y=mx+b

Answer 3

Perfect, so, all you're going to do is move the symbols/numbers around so it looks the same as that.

Answer 4

5x-y=7

We will leave y on the left because that's where we want it.
Subtract 5x from both sides: -y=7-5x
Divide both sides by -1 to get rid of the - on the y: y=-7+5x
Switch the places of the -7 and 5x so it looks like the form you gave:
y=5x-7

m=5 and b=-7

Answer 5

Then what would the second one be?

Answer 6

Give it a shot and I'll help you work through it

Answer 7

I can't figurte this one out, I think it's like y=5 then I get lost

Answer 8

2x + 5y= 15

Do it one step at a time. Try to get y by itself. You can't divide both sides by 5 to get rid of the 5 next to the y until you get rid of that 2x. What can you do to get rid of the 2x on the left?

Answer 9

Divide by twp on both sides?

Answer 10

Well, you want to get rid of the whole 2x not just 2. So, look at that as a chunk by itself. 2x is being added to 5y. What's the opposite of addition?

Answer 11

subtraction

Answer 12

So, subtract 2x from both sides. What do you get?

Answer 13

Here is a short video that shows how to do this
http://www.khanacademy.org/math/algebra/linear-equations-and-inequalitie/v/converting-to-slope-intercept-form