A system of equations is set up to determine the number of nickels and the number of quarters Elissa has. Which ordered pair does NOT represent a valid solution to this system?

a. (0,15)
b. (12,-5)
c. (31, 4)
d. (7,0)

please explain how to do this too!

Question

A system of equations is set up to determine the number of nickels and the number of quarters Elissa has. Which ordered pair does NOT represent a valid solution to this system?

a. (0,15)
b. (12,-5)
c. (31, 4)
d. (7,0)

please explain how to do this too!

wolf1728 · Answer

I'm assuming that the ordered pairs represent the
(# of nickels, # of qrtrs)
OR
(# of qrtrs, # of nickels)
Without even doing any calculations, we can look at the four answers and see that
b. (12,-5) cannot be a result.  How can anyone have -5 nickels or -5 quarters?