Answer:
y- intercept = - 2.5
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m =
with (x₁, y₁ ) = (1, - 7) and (x₂, y₂ ) = (5, - 25)
m = =
= - 4.5 , then
y = - 4.5x + c
To find c substitute either of the 2 points into the equation
Using (1, - 7), then
- 7 = - 4.5 + c ⇒ c = - 7 + 4.5 = - 2.5
y- intercept c = - 2.5
Using proportions, it is found that the speed of the runners are of 16 mph and of 20 mph.
<h3>What is a proportion?</h3>A proportion is a fraction of a total amount.
After 30 minutes, the runners are 2 miles apart, hence the second runner is 4 miles per hour faster than the second, that is:
.
The first runner's speed is 4/5 of the speed of the second runner, hence:
Hence, the speed of the runners are of 16 mph and of 20 mph.
More can be learned about proportions at brainly.com/question/24863377