Does someone knows how to solve this. Step by step?

Completing the Square:

x^2-6x=15

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?

Which represents the inverse of the function f(x) = 4x? h(x) = x + 4 h(x) = x – 4 h(x) = x h(x) = x

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?