passing through (3,5) and (8,15)

Question

I am trying find equaption for it

Answer 1

Slope or m = (y₂ - y₁)/(x₂ - x₁₎

 

y₂ = 15; y₁ = 5; x₂ = 8; x₁ = 3

 

(15 - 5)/(8 - 3) = 10/5 = 2 = m

 

y = mx + b with b = y when x = 0

 

   = 2x + b

 

With (3,5):

 

5 = 2(3) + b

 

5 = 6 + b

 

-1 = b

 

Let's check with (8,15)

 

15 = 2(8) + b

     

    = 16 + b

 

-1 = b

 

y = 2x - 1

 

 

Answer 2

The equation of a line is in the form  y=mx+b , where m is slope and b is y-intercept.

 

First we find the slop between these lines. Slope is change in y over change in x.

 

m = (15 - 5) / (8 - 3)

m = 10 / 5

m = 2

 

 

y = 2x + b

 

Next we plug in the values of point (3, 5) into the equation to find b.

 

 

5 = 2(3) + b

 

5 = 6 + b

 

-1 = b

 

 

The equation is

 

y = 2x - 1