17-5x=3
Flip 17 and 5x, and since its subtraction it'll be -5x as shown below...
-5x-17=3
Now, instead of subtracting 17 you would do the opposite in this case add 17 by 3 this equals 20. 20 equals to -5x.
-5x - 17=3
17+3=20
---------------
-5x = 20
Now you divide -5x by 20, which would be -5.
X= -5
to check my answer i did, -5×(-5)
which is 20. 20-17=3.
I hope this helped.