Question

Which is not an equation of the line that passes through the points (1, 1) and (5, 5)?

y - x = 0
x - y = 0
-x - y = 0

Answer 1

-x-y=0 is not a line that passes through (1,1) and (5,5). All you have to do is plug the points in to each equation and see which one doesn't work!

Answer 2

Answer:
`-x - y = 0`

Explanation:

The equation of line passing through two points (a,b) and (c,d) is given by :-

`(y-b)=(d-b)/(c-a)(x-a)`

Then , the equation of line passing through two points (1, 1) and (5, 5) is given by :-

`(y-1)=(5-1)/(5-1)(x-1)\\\\\Rightarrow\ y-1=x-1\\\\\Rightarrow\ y=x`

It can be written as
`y - x = 0\ or\ x-y=0`

Hence, the
`-x - y = 0` is not an equation of the line that passes through the points (1, 1) and (5, 5).