Hello :3
To get your answer we need to subtract, add, and multiply. (I do the PEMDAS thing so it might sound a little weird)
First, we always do parentheses,
2x + 4 = 6x
Next, (since there's no exponents), we need to multiply
6x x -6 = -36x
Now,(since there's no division), we need to add.
-36x + 8 = -28x
So, your answer would be -28x (since there's no subtraction).
Hope This Helps!
Cupkake~
