Question

A line passes through (2, −1)(2, −1) and (4, 5)(4, 5).

What is the equation of the line?

Answer 1

First find the slope by using the slope formula
a line goes through two points \((x_1,y_1)\) and \((x_2,y_2)\)
Slope=\(\Large\frac{y_2-y_1}{x_2-x_1}\)

Answer 2

I did that. I got 3 for the slope.

Answer 3

why have you written the points twice?

Answer 4

@MrNood He hasn't. Openstudy sometimes copies it for some weird reason

Answer 5

Good job, it is 3 @timinthor

Answer 6

Now, plug that into the equation
y=mx + b

m = slope

Use a given point to plug in for y and x and solve for b

Answer 7

So y=3x+b but how do i find b? @StudyGurl14

Answer 8

Use a given point. (2,-1) for example
Remember that a point is (x,y)

Plug in for x and y in the equation and solve for b

Answer 9

So -1=3x+2?

Answer 10

Do you solve like a normal equation? @StudyGurl14 If so,
-1=3x+2
-2 -2
-3=3x
-3/3
x=-1?
But it asks for the equation. None of the answers look like that though. The answer choices are:
A. −3x+5y=−13

B. −3x+y=−7

C. −3x+5y=13

D. −3x+y=17

Answer 11

No, you plugged in 2 for b, not x.

y = mx + b
y = 3x + b
(-1) = 3(2) + b

Now solve for b

Answer 12

-7? @StudyGurl14

Answer 13

yep. so you get
y = 3x - 7

Answer 14

Thanks!

Answer 15

:)