Solve both with work

Find the solution of system of equation y= x-4 y=4x+2

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?

Suppose that the function f is defined. , for all real numbers, as follows. _ \ 1/4x² -4 if x≠ -2 f(x)=< /_-1 if x=-2 find f(-5), f(-2), and f(4)