00:01
Okay, so i have a situation with some movie tickets, and i know adult tickets are $8, children's tickets are $5, 40 people were there all together, and the theater collected $272.
00:17
Okay, and i want to know how many are adults.
00:20
So i'm going to let the adults be represented with an a and children with a c.
00:28
So i know that adults plus children, the number of adults plus the number of children have to equal 40 people.
00:40
I also know that the adults pay $8 a ticket, the children pay $5 a ticket, and altogether that's going to equal $272.
00:56
I'm going to rewrite this top function so that it says children equals $272.
01:02
So i'm going to subtract a from both sides, and i get children equals 40 minus a.
01:12
I'm doing that because i'm going to now go to the second equation with that new expression, and instead of saying 5 times c, i'm going to say 5 times 40 minus a.
01:27
Let me underline that in another color, so you can see that clearly.
01:31
I'm taking the 40 minus a that i know c equals, and i'm going to be...