Question

If a line contains the point (0, -1) and has a slope of 2, then which of the following points also lies on the line?

Answer 1

y=2x-1

Explanation:

y-y1=m(x-x1)

y-(-1)=2(x-0)

y+1=2(x)

y+1=2x

y=2x-1

Answer 2

See Explanation below

Explanation:

Topic: Gradient and Slope

To get the other points, first, we must calculate the equation of the line using the slope formula.

Given

Point (0, -1)

Slope, m = 2

The Slope of a line is calculated by
`m = (y - y_(1) )/(x - x_(1))`

Given that a point on the line is (0, -1), then
`(x_(1) , y_(1)) = (0, -1)`

Substitute each of these values in the formula above, we have

`2 = (y - (-1) )/(x - 0)`

`2 = (y + 1 )/(x)`

`2x = y + 1` --- Make y the subject of formula

`y = 2x - 1`

This equation can then be used to get the other points that lies on the slope.

Take for instance Point
`(x , y) = (4, 7)`

By Substitution, we have

`y = 2x - 1` becomes

`7 = 2*4 - 1`

`7 = 8 - 1`

`7 = 7`

Hence, the point
`(4, 7)` lies on the plane