Which sentence is the most accurate definition of an identity?

An identity is an equation that is true for all real numbers.

An identity is an equation that is true for all real values in its domain.

An identity is an equation that is true for all real values in its range.

An identity is an equation that can be verified by substituting input values.

Option b is the right answer

y=3x+4

step-by-step explanation:

given the points a(0,4) and b(-4, -8)

eqn of line ab: (y-4)/(x-0)=(-8-4)/(-4-0)

(y-4)/x=-12/-4=3

y=3x+4