Answer: Hope this helps
Step-by-step explanation: Subtract 4 from 8 means 8-4.
You just combine like terms. Since you are subtracting 5x^2-7x-6 from 9x^2+3x-4, you would have to change all the signs. For instance:
9x^2+3x-4-(5x^2-7x-6)=
9x^2+3x-4-5x^2+7x+6
Combine like terms
4x^2+10x+2
Hopefully, that helps you.