Question

3x+y=7 for y

Answer 1

Basically, you're trying to isolate the y... 3x is being added to y. What do you do to make a positive 3x to make it equal zero? Perform this on both sides of the equation.

Answer 2

can u write out the steps so i can c how the to solve it

Answer 3

I can't really give you a full answer, but I can show you an example that is very similar...
Solve for y.
5x + y = 2
- 5x + 5x + y = 2 - 5x
0 + y = 2 - 5x
y = 2 - 5x
Do you get it?

Answer 4

that was not the right problem. the problem is 3X+y=7 for y

Answer 5

Yes. I said that it was an EXAMPLE. It is very similar to the actual problem...

Answer 6

i do not understand what u just did

Answer 7

Ok. Maybe this will help...
Solve for y in the following problem.
5x + y = 2 This is the example problem.
- 5x + 5x + y = 2 - 5x Subtract 5x from both sides.
0 + y = 2 - 5x Do you see how 5x - 5x = 0? I just combined like terms.
y = 2 - 5x 0 + anything is what was being added to 0.

Answer 8

So do the same thing in the original problem.
3x + y = 7 This is the problem.
3x - 3x + y = 7 - 3x Subtract 3x from both sides.
0 + y = 7 - 3x Combine like terms.
y = ???? Can you do what's above??