Question

What is the equation of the following line written in general form? (The y-intercept is -1.).

A. -2x - y - 1 = 0
B. 2x + y - 1 = 0
C. 2x - y - 1 = 0

Answer 1

The answer is C.

Explanation:

In the graph above, it is a positive gradient so option A and B cannot be applied.

Next you have to look at the y-intercept where the line touches the y-axis so -1 is the y-intercept.

The slope-form equation is y = mx + b where m represents gradient amd b is y-intercept :

Option A,

`- 2x - y - 1 = 0`

`y = - 2x - 1 \: (incorrect \: m)`

Option B,

`2x + y - 1 = 0`

`y = - 2x + 1 \: (incorrect \: m \: and \: b)`

Option C,

`2x - y - 1 = 0`

`y = 2x - 1 \: (correct \: m \: and \: b)`