Standard form of (2,-4) slope : - 1

Y = mx + b

slope (m) = - 1

(2,-4) ... x = 2 and y = - 4

now we sub and find b, the y int

-4 = - 1 (2) + b

-4 = - 2 + b

-4 + 2 = b

-2 = b

y = - x - 2

x + y = - 2 < = = standard form