Evaluate y' at (2,1) [Implicit differentiation]

Question

5xy-3x-4=0

I got 3/10 and 2/10 but both were wrong.

Answer 1

What do you mean by "both" ?
(2,1) is the single point where x=2 and y=1.

Using implicit differentiation to get dy/dx, consider y to be a function of x and differentiate both sides. This results in
5x dy/dx + 5y -4 = 0
When x=2 and y=1,
10 dy/dx + 5 -4 = 0
dy/dx = -1/10

Answer 2

By both, I mean I got my answer to be 3/10 and 2/10 but they weren't correct.

I tried -1/10 and it was wrong.

Answer 3

The answer is -2/10.

Answer 4

5x dy/dx + 5y -4 = 0
There was a typo. the -4 should read -3.
You will get -2/10 or -1/5.