Answer:
-3x-12
Explanation:
This is a problem of distribution.
Distribute means to multiply the variable outside the perenthesis to what's inside the perenthesis.
What you are going to do is distribute the -3 to the x and 4
-3 times x is -3x
-3 times 4 is -12
Make sure the signs are correct and the new expression is -3x-12