The Bradys and their maid, Alice, took a trip to Hawaii for their summer vacation. The travel agent told Ike that the trip would cost $210 for each child plus another $315 per adult. According to the credit card receipt the trip cost a total of $2205 for all 9 of them. Find the number of adults and children on the trip by writing a system of equations. PLEASE EXPLAIN HOW YOU GOT THE ANSWER. I HAVE ALOT OF QUESTIONS LIKE THIS ONE SO I NEED TO KNOW HOW YOU GOT THE ANSWER. THANK YOU!

3 answers

2205 - (315 * 3) = ?

Divide the above answer by 210 to find the number of children.
or

number of children --- c
number of adults ---- a
a+c = 9
c = 9-a

210c + 315a = 2205
210(9-a) + 315a = 2205
1890 - 210a + 315a = 2205
105a = 315
a = 3
c= 6

3 adult and 6 children
check: 1+8 = 9
210(6) + 315(3) = 2205
Just realized I answered the same question over 2 years ago

http://www.jiskha.com/display.cgi?id=1421083338