Question

How do you write an equation in standard form given that the line passes through (-1, -3) and (2, 1)?

Answer 1

Using this formula with the given points:
`(x-x_0)/(x_1-x_0)=(y-y_0)/(y_1-y_0)`

The points are:

• `A(x_0,y_0)->A(-1,-3)`
• `B(x_1,y_1)->B(2,1)`

So the equation of the line passing through A and B becomes:
`(x-(-1))/(2-(-1))=(y-(-3))/(1-(-3))`

`(x+1)/(2+1)=(y+3)/(4)`

`(x+1)/3=(y+3)/(4)`

Now we must bring the equation in a "standard form" that means an equation similar to `ax+by+c=0`

`4*(x+1)=(y+3)*3`

`4x +4 = 3y + 9`

`4x-3y-5=0`

graph{4x-3y-5=0 [-3, 3,-3,3]}