Simplify 6 -square root of 15 divided by 2

Which of the following system of equation is not equal to the system of equations is not equal to the system of equations shown below

Ireally need subtract and simplify.(-y^2 – 4y - 8) – (-4y^2 – 6y + 3)show your work, ! i will mark you brainliest but you have to show your work.

What is the factor form of x^2-9x+14