## vickie19 3 years ago 3x+y=7 for y

• This Question is Open
1. Calcmathlete

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.

2. vickie19

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

3. Calcmathlete

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?

4. vickie19

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

5. Calcmathlete

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

6. vickie19

i do not understand what u just did

7. Calcmathlete

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.

8. Calcmathlete

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??