We have 2 types of tickets, A tickets and B tickets. The total number of tickets sold was 500, so an equation for this NUMBER of tickets is A + B = 500. The MONEY equation is something different. A tickets cost 10, so they are represented by 10A; B tickets cost 60, so they are represented by 60B. The total dollar sales for A and B are 6000. Our money equation for the sales is 10A + 60B = 6000. Solve the first equation for A: A = 500 - B. Sub that value for A into the second equation to solve for B: 10(500-B) + 60B = 6000. Distribute through the parenthesis to get 5000 - 10B + 60B = 6000. Combine like terms to get 50B = 1000. B = 20. There were 20 type B tickets sold. A = 500 - B, so A = 500 - 20 and A = 480. There were 480 type A tickets sold.
ALEXIS SPENT 3 hours and 15 minutes away from home and 2 hours and 45 min is part B
Rearrange the 2nd equation
-36a-24b-16c
divide the whole thing by 4 and you'll get
-9a-6b-4c
you'll realize it looks the same as your first equation except that all the + has become minus so the answer will be -7 instead for your new equation
-9a-6b-4c=-7
multiply the whole thing by 4 and you'll get
-36a-24b-16c = -28
so the answer you want is -28