I'm confused!?

Question

How does
13y-18= -5y+36
I know that y=3 bu I always get y=6.75!
Please show me what to do!

Answer 1

To solve it you have to get the y's to stand alone on one side. To do that, you should start out by getting all the y's on the same side.
1) You want to get the -5y on the left side, so you have to add 5y to each side: 13y +5y -18= -5y+5y+36
2) Your equation now looks like this: 13y+5y-18=36
3) Now that you have the y's on one side, you can collect like terms. You can add 13y and 5y to get 18y.
4) Your equation now looks like this: 18y-18= 36
5) You want the y alone on one side, so first you want to move the -18 to the other side: 18y -18+18= 36+18
6) Your equation now looks like this: 18y=54
7) You still have the 18 attached to the y, and you want the y seperate. To get rid of the 18, you have to divide each side by 18: 18y/18=54/18
8) Your equation now looks like this: y= 3
9) Now check your answer, and replace the y's with 3's.

(You should always do the subtraction/addition before multiplication/division, in solving unknowns. It sounds weird, because the order-of-operations is the other way, but it's easier to do it this way, in these kind of equations--only. If you did division first, you would have ended up with y=20.)

Answer 2

13y - 18 = -5y + 36
18 = 18
13y = -5y + 36 + 18 see, I added the above equations.
5y = 5y
13y + 5y = 36 + 18 see, I added the above equations
18y = 18 * (2 + 1) simplifying
18 = 18
y = 3 I divided!

Answer 3

13y-18= -5y+36

18y=54

y=3

Collect like terms then divide both sides by 18.

Answer 4

13x3=39
39-18=21
-5x3=-15+36=21