Using substitution how do you solve -4x+y=6 -5x-y=21

Which type of graph would allow us to quickly see how many students between 100 and 200 students were treated?

Rob filled 5 fewer plastic boxes with football cards than basketball cards. he filled 11 boxes with basketball cards.

For which pairs of functions is (f•g)(x)=12x? f(x)=3-4x and g(x)=16x-3 f(x)=6x2 and g(x)= 2/x f(x)= and g(x) = 144x f(x)=4x and g(x) =3x