Question

Choose the equation of the horizontal line that passes through the point (1, 7) and (5, 15) using function notation​

Answer 1

f(x)=2x+5

Explanation:

Using standard slope-intercept form of y=mx+b,

The slope is (15-7)/(5-1)=8/4=2

now, we have y=2x+b

To find b, we have to plug in a point:

7=(2)(1)+b

b=7-2

b=15

y=(2)x+5

function notation: replace y with f(x)