Question

What is the equation of the line that passes through (-1,-4) and (2,5)

A. y+1=3(x+4)
B. y+4=-3(x+1)
C. y+4=3(x+1)
D. y-4=-3(x-1)

Answer 1

c) y+4=3(x+1)

Explanation:

Answer 2

C.
`y+4=3(x+1)`

Explanation:

Hi there!

What we need to know:

• All the given equations are in point-slope form:
  `y-y_1=m(x-x_1)` where m is the slope and the given point is
  `(x_1,y_1)`

1) Determine the slope of the line

`m=(y_2-y_1)/(x_2-x_1)` where the given points are
`(x_1,y_1)` and
`(x_2,y_2)`

Plug in the points (-1,-4) and (2,5)

`=(5-(-4))/(2-(-1))\\=(5+4)/(2+1)\\=(9)/(3)\\=3`

Therefore, the slope of the line is 3. Plug this into
`y-y_1=m(x-x_1)` :

`y-y_1=3(x-x_1)`

2) Plug the point (-1,-4) into
`y-y_1=3(x-x_1)`

`y-(-4)=3(x-(-1))\\y+4=3(x+1)`

Therefore, the correct answer is C.

I hope this helps!