Rachel drives 113 miles from Pittsburg to Cleveland averaging 30 miles per hour. How fast must she drive on the return trip to average 60 miles per hour overall?

90 mph

Step-by-step explanation:

Average speed is given by

Average speed=(initial+final speed)/2

Given average speed of 60 mph then considering initial speed of 30 mph. Let x be the final speed hence

60=(30+x)/2

120=30+x

X=120-30=90 mph

Therefore, the return trip speed is 90 mph

step-by-step explanation:

let

we know that

the y-intercept is the y-coordinate of the point when the value of x is equal to zero

so

the y-coordinate of the point a is the y-intercept

the answer part a) is

the value of y-intercept is

part b) find the slope m

we know that

the value of the slope is equal to

substitute the values

therefore

the answer part b) is

the value of the slope is equal to

the general answer is

the slope is

the value of y-intercept is