which best describes the system of equations?

3x = 5 − 4y
6x + 8y = 7

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?

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

X-intercept=-5 y-intercept=2 the equation of the line is