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

The third option.  you can always substitute the points into your equation to see if the equation is true or not.

Answer 2

-x-y=0 is not the equation of the line

Explanation:

Lets find equation of a line that passes through points (1, 1) and (5, 5)

Slope =
`(y2-y1)/(x2-x1) =(5-1)/(5-1) =1`

Slope = 1 and use point (1,1)

y-y1= m(x-x1)

y-1= 1(x-1)

y-1 = x-1

add 1 on both sides

y=x

when we subtract x on both sides then equation becomes y-x=0

when we subtract y on both sides then equation becomes x-y=0

so -x-y=0 is not the equation of the line