To check if an ordered pair is a solution to an equation, substitute the value for each coordinate into the equation.
Since the substitution has to be performed in alphabetical order, then the coordinates are given in the form:
Substitute r=-6 and s=-2 into the given equation to check if (-6,-2) is a solution:
Since -4 is NOT equal to 4, then the point (-6,-2) is not a solution to the equation r-s=4.