Answer:
1. 3x(4-x)
2. 20(1-12x^2)
Step-by-step explanation:
1. Both of the monomials have an x and can be divided by 3. You can factor out 3x, getting the equation I wrote out on the answer part.
2. Both of the monomials can be divided by 20, so you can once again factor out 20, getting the equation I wrote out on the answer part.