The family fine arts center charges $21 per adult and $13 per senior citizen for its performances. on a recent weekend evening when 535 people paid admission, the total receipts were $8355. how many who paid were senior citizens?
i am struggling with the right formula to use.
do i use an arthimetic or geometric sequence?

175 adults

360 senior citizens

Step-by-step explanation:

Let x be the number of senior citizens

There were a total of 535 people, so

(535-x)=total number of adults

Total receipts=$8,355

Adult payments+Senior payments=$8,355

21(535-x)+13x=$8,355

$11,235-21x+13x=$8,355

$11,235-8x=$8,355

-8x=$-2,880

x=360 senior citizens

Number of adults=535-360=175 adults

To check, just substitute...

21(175)+13(360)

3,675+4,680

Which equals

$8,355

answer: it is 8

step-by-step explanation:

you know why its 8

1/2(2*4)=6 $$- agahajakanajak