Question

How do you graph `2x + y = –1` by plotting points?

Answer 1

See a solution process below:

Explanation:

First, solve for two points which solve the equation and plot these points:

First Point:

For `x = 0`

`(2 * 0) + y = -1`

`0 + y = -1`

`y = -1` or `(0, -1)`

Second Point:

For `y = 0`

`2x + 0 = -1`

`2x = -1`

`(2x)/color(red)(2) = -1/color(red)(2)`

`x = -1/2` or `(-1/2, 0)`

We can next graph the two points on the coordinate plane:

graph{(x^2+(y+1)^2-0.025)((x+1/2)^2+y^2-0.025)=0 [-10, 10, -5, 5]}

Now, we can draw a straight line through the two points to graph the line:

graph{(2x+y+1)(x^2+(y+1)^2-0.025)((x+1/2)^2+y^2-0.025)=0 [-10, 10, -5, 5]}