How do you write the equation of the line in slope intercept form passing through (1, 2) and (2, 5)?

3 Answers
Apr 20, 2018

y = 3x -1

Explanation:

  1. Find the slope by using the formula y2y1x2x1
    You wil get: 5221
    Simplify to get 3

  2. Find the y-intercept by plugging in one kf the pairs and the slope into the y = mx + b equation. It doesn’t matter which pair you use.

You see 2 = 3(1) + b
Solve for b
2 = 3 + b
-1 = b

  1. Answer is y = 3x -1
Apr 20, 2018

y=3x1

Explanation:

the gradient/slope is the difference in the y values divided by the difference in the x values.

5221 =31 =3

so the equation of the line is y=3x+c

Use (1,2) 2=3×1+c
2=3+c so c=-1

this gives y=3x1

Apr 20, 2018

y=3x1

Explanation:

the equation of a line in slope-intercept form is.

xy=mx+b

where m is the slope and b the y-intercept

to calculate m use the gradient formula

xm=y2y1x2x1

let (x1,y1)=(1,2) and (x2,y2)=(2,5)

m=5221=3

y=3x+bis the partial equation

to find b substitute either of the 2 given points into
the partial equation

using (1,2) then

2=3+bb=23=1

y=3x1equation in slope-intercept form