Question

Write the equation of the line in slope intercept form that passes through the points (-1,1) and (2,13)

Answer 1

The slope-intercept form:

`y=mx+b`

m - slope

b - y-intercept

The formula of a slope:

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

We have the points (-1, 1) and (2, 13). Substitute:

`m=(13-1)/(2-(-1))=(12)/(3)=4`

Therefore the equation of a line is

`y=4x+b`

Put the coordinates of the point (2, 13) to the equation of a line:

`13=4(2)+b`

`13=8+b` subtract 8 from both sides

`5=b\to b=5`

Answer: y = 4x + 5