if 3+x / 7+x = 3/7 + 3/7, then x= what

2 answers

Don't post the same question using different names please.
Well, the spacing makes me interpret this as

(3+x)/(7+x) = 3/7 + 3/7

I still suspect a typo on the right side, but now at least we have

(3+x)/(7+x) = 6/7
7(3+x) = 6(7+x)
21+7x = 42+6x
x = 21