Description: Sal demonstrates solving a word problem by writing a system of equations and solving using the elimination method. And he says, well I know adults eat a different number of cupcakes than children eat. And I know that in my kingdom, an adult will always eat the same amount and a child will always eat the same amount. And he says, well I know at the last party we had 500 adults and we had 200 children, and combined they ate 2,900 cupcakes.*Teacher Advisor is 100% free.