Tickets at the theater or $9 for adults seniors receive a discount and only have to pay $6 but capicity of the theater is 80 people. If the theater was at full capacity and made $675, then how many seniors bought tickets for the movies? And how did you get that answer

So $9 for adults and $6 for seniors

so number of adults is represented by x

number of seinors is represented by y

9x+6y=675 since every adult pays 9 and seinors pay 6

x+y=80 since adults+seinors=80

multiply x+y=80 by - 6

-6x-6y=-480

add this to 9x+6y=675

9x-6x+6y-6y=675-480

3x+0=195

divide both sides by 3

x=65

there were 65 adults

subsitute 65 for x in x+y=80

65+y=80

subtract 65 from both sides

y=15

there were 15 seinors at the event