When you are solving a system of equations using the addition method?

Question

how do you know when the lines are parallel or equal?

Answer 1

you know that the lines are parallel if when you add the two equations you get something false like 0=5

you know that they are the same line when you get something true like 0=0

Answer 2

Lines are equal if one equation of the line is a multiple of the other in all coefficients. Lines are parallel when the x and y coefficients of one equation are the same multiples of the x and y coefficients of the other equation, and constants are different.

Answer 3

you know that the lines are parallel when the slope of both equations are equal.. slope meaning the number before the x in an equation.