Question

How do you write the equation of the line that passes through the points (1, 7) and (5, 15) using function notation?

Answer 1

The equation of the straight line is `2x-y+5=0`.

Explanation:

The equation of a straight line*" that passes through the two points, `(x_1,y_1)` &`(x_2,y_2)` & whose slope is `m`** is:

`y-y_1=m(x-x_1)`, or,
`y-y_1=((y_2-y_1)/(x_2-x_1))(x-x_1)`.

So, the equation of the st.line which passes through the points `(1,7)` & `(5,15)` is:

`y-7=((15-7)/(5-1))(x-1)`.
`:.y-7=8/4(x-1)`.
`:.y-7=2(x-1)`.
`:.y-7=2x-2`.
`:.2x-y+5=0`. (Answer).