-11 + 4(3+1) + 3(5-9) + 7(6-8) + 25

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2