You'll need to use parentheses here to convey this problem accurately to possible helpers. Unsure of whether you mean (9/2)k -3 or 9 / (2k-3).
I will assume that you mean:
9 4
------- = ---------
2k-3 k+1
Cross mult: 9k+9=8k-12, so k= -21.
If that's not what you expected, then try again to present the problem without ambiguities.