Y = 3r +21
Which ordered pair is a solution to the equation?

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?

Evaluate the expression for the given value of the variable. 5×(h+3) for h=7

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota