Im almost done with my math homework pls help

When using the linear combination metho e linear combination method to solve a system of linear equations, the four options are:

What is the effect on the graph of the function f(x)=x when f(x) is replaced with -f(x)+4

The graph of a function f(x)=(x+2)(x-4). which describes all of the values for which the graph is negative and increasing? all real values of x where x< -2 all real values of x where -2