X is cheeseburgers and y is hamburgers
x + y= 351
2x+y=351
Now I can do 351 divided by 3 which gives me 117. Since 117+117+117 is 351 and the number of cheeseburgers sold was twice the amount as hamburgers. I will say that there was 117+117 cheeseburgers sold and there were 117 hamburgers sold.
Hope it makes sense.....
If there are only two options, and one is double of the other, then one is 2/3 and the other is 1/3 of the question (total being 3/3, or one whole) So...351/3=117, so 117 hambergers were sold.117*2=234, so 234 cheeseburgers were sold
