Help me please I
Don’t understand

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?

He that is measured at 220° is a reflex angle. the opposite angle is obtuse. find the measure of obtuse .

Identify the expression equivalent to 4(x + x + 7) − 2x + 8 − 4 by substituting x = 1 and x = 2.