Which expression is easier to simplify

Pranza plotted point a in the coordinate plane below.

Which of the following points is a solution to the system of equations shown? y - x = -1 x + y = -5

Shannon mary and john earn a weekly allowance ahannon earns the amount that is 2/3 of what john earns mary earns an amount that is 1 2/3 of what johns earns 20 dollars a week who eaens the greatest allowance and who earns the least