Question

A restaurent sold 350 less hotdogs than hamburgers. Altogether, the restaurant sold 700 hotdogs and hamburgers. How many of each did they sell?

Answer 1

Let x=number of hamburgers, so number of hotdogs is x-350.
Altogether x+x-350=700, 2x=1050, x=525, so the number of hamburgers is 525 and the number of hotdogs is 175.

Answer 2

Let d=# of hot dogs, and b=# of burgers.  d+b=700, and d = b-350.

d + b = 700 becomes b-350 + b = 700.   => 2b= 1050; b = 525.

Then d=525-350 = 175.

They sell 175 hot dogs and 525 burgers.

Do 175 and 525 add up to 700?   yes.