Help with math homework? EASY! y=mx+b

So I'm confused on how to put an equation into y=mx+b form. Of course I know HOW I just get confused whether you add or subtract it...so if the equation is 3x+y=7 here's how you would solve it
3x+y=7
+3 +3
y=3x+7
AM I RIGHT?

If so how would you solve: 2x-5y= -1

You are wrong. You must get y by itself and it must be positive. In your example you would subtract 3x.
3x+y=7
-3x -3x
y= -3x+7

2x-5y= -1
2x = 5y-1
2x+1=5y Now divide both sides by 5 to get y by itself
(2/5)x+1/5=y

No you would have to subtract it because it's a positive three so you do the opposite of what the number is
3x+y=7
-3x=-3x
y=-3x+7

2x-5y=-1
-2x=-2x
-5y=-2x-1
Divided both sides by -5 and divid every single number so
y=2/5+1/5

It's positive now because you took a negative number and divided it by another negative which makes it positive.

The goal is to isolate the "y" variable. In your first equation you would have to SUBTRACT the term "3x" from both sides since it is positive. So, with that said, you would have y = -3x+7 . In the second one, there are several ways to solve it. To have "nice" signs I would first add 5y to both sides since it is negative. Then I would add 1 to both sides since it is negative. Since I only want y, I would have to get rid of the the coefficient 5 by dividing by 5 from both sides. Therefore, you'd get (2/5)x + (1/5) = y.

no the answer is y=-3x+7 because you subtract 3 from both sides because it is positive

2x-5y=-1
-2x -2x
-5y=-2x-1
divided by -5

y=2/5x+1/5

Hope this helps!

3x + y = 7

to get y by itself subtract 3x from both sides y = 7 - 3x

2x -5y = -1
subtract 2x from both sides

-5y = -1 -2x
change signs on both sides

5y = 2x + 1