Question

willing to give a medal and become a fan ^.^
find the range of each function for the given domain.
18- f(x)=2x-7; {-2, -1, 0, 1, 2}
19- g(x)=-4x+1; {-5, -1, 0, 1, 2, 10}
20- h(x)=x^2; {-1.2, 0, 0.2, 1.2, 4}
21- f(x)=8x-3; {-1/2, 1/4, 3/4, 1/8}

sorry if this is too much, i just don't really understand how to find the range of a function.. i'd greatly appreciate if you could help me out with the answers. xx