rx=11x+7, solving for x

[darktactics]

Hi, I'm reviewing some algebra problems, and I don't know what the steps are to solve this problem. I already know my answer is wrong, but i'll post here just to show that I tried:

steps:
1. rx=11x+7 (subtract 11x both sides)
2. r-10x=7 (divide by r)
3. -10x = 7/r (divide by 10)
4. -x = 7/r/10 (inverse sign)
5. x = -(7/r/10)

 

[Quaid]

r - 10x = 7

(divide by r)

-10x = 7/r

That's not the correct way to divide (r - 10x) by r.

When we divide the left-hand side, each term gets divided by r.

r/r - 10x/r = 7/r

1 - 10x/r = 7/r

Of course, Denis explained that r-10x is wrong, so you don't want to use it.

But, next time you divide a polynomial by a constant, remember to divide each term of the polynomial by the constant.