The sign that should be between -8x and 60 is the plus sign (+) for addition.
The equation should look like this:
-8x + 60 = 28
Find x. Transfer 60 to the other side and change its sign from positive to negative
-8x = 28 - 60
-8x = -32
Find x. divide both sides by -8
-8x / -8 = -32 / -8
x = 4
To check: substitute x by its value.
-8x + 60 = 28
-8(4) + 60 = 28
-32 + 60 = 28
28 = 28