9(4 - s) = 10 + 4s
what is the answer?

Before you can do anything, you need to get rid of the parenthesis so you can deal with the numbers inside them.

Distribute the 9:
36-9s=10+4s

Combine like terms (I subtracted the 10 from 36 and added the -9s to 4s)
26=13s

Divide by 13 to get s alone

s=2

Hope this helps

36-9s=10+4s
36=10+13s
26=13s
2=s

Hope this helps :)