Question

What is the equation of a line, in the form `ax+by+c=0`, with gradient -2 through the point (4, -6)?

Answer 1

First, we should know that slope of linear equation is `m=(y1-y2)/(x1-x2)` and we can form the equation by this formula.

In this case, we have gradient (slope)= `-2` and the point (4, -6). We can just simply sub the things we know into the above equation.

So, the equation will be:
`-2= (y-(-6))/(x-4)`
`-2(x-4)=y+6`
`-2x+8=y+6`

And we can change it in the form `ax+by+c=0`, which is
`-2x-y+2=0`