Question

A line passes through the points (5,20) and ( 7 , 22). Write a linear function rule in terms of x and y for this line.

Answer 1

y = x + 15

Explanation:

The slope-intercept form of an equation of a line:

`y=mx+b`

The point-slope form of an equation of a line:

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

m - slope

(x₁, y₁) - point

The formula of a slope:

`m=(y_2-y_1)/(x_2-x_1)`

We have the points (5, 20) and (7, 22). Substitute:

`m=(22-20)/(7-5)=(2)/(2)=1`

`y-20=1(x-5)`

`y-20=x-5` add 20 to both sides

`y=x+15`