Answer:
1) 12x-4
2) 5x^2+6x-3
Step-by-step explanation:
For number one, just multiply 3x-1 by for using the distributive property.
This would be 4(3x-1) = 12x-4.
For the second question, you know that you need to add something to 2x^2-6x-12 in order to get 7x^2-15.
2x^2 + ? =7x^2. The question mark would be 5x^2.
You can see that there is no x variable in 7x^2-15. That means you just need to take the opposite of -6x, which is 6x.
Finally to go from -12 to -15, you need to subtract 3.
This will leave you with 5x^2+6x-3
