Question

What is the equation of the line passing through `(1,2)` with slope `m= -5`?

Answer 1

`y=-5x+11`

Explanation:

The equation of a line is `y=mx+c`. We are given the value for `m`, `m=-5`.
We can substitute this into the equation `y=mx+c` to get `y=-5x+c`
We are also given the point `(1,2)`
This means when `y=1`, `x=2`
We can use this information to substitute it into our line formula to get `1=-5(2)+c`
From this we can work out what c would be (by rearranging)
`1=-10+c` then turns into `1+10=c=11`, which we can then substitute into out original formula to get `y=-5x+11` or `11-5x-y=0`