write the equation of the line in either form (slope intercept or point slope form) that contains points (4,-5) (8,1)

y = x - 11

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 ) = (4, - 5 ) and (x₂, y₂ ) = (8, 1 )

m = = = = , then

y = x + c ← is the partial equation

To find c substitute either of the 2 points into the partial equation

Using (8, 1 ) , then

1 = 12 + c ⇒ c = 1 - 12 = - 11

y = x - 11 ← equation of line in slope- intercept form

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.