y = Acos(Bx) + D;
D = 4, A = 2. Now T = 2π/B = 5π/8, B = 2π/(5π/8) = 16/5
WE get y = 2cos(16/5x) + 4
Answer: 8 whole gallons.
Step-by-step explanation: If you have only $27.00 and you need to buy gas, but each gallon is $3.15, then you just need to divide your total amount ($27.00) by your cost per gallon ($3.15), and you will get about 8.6 gallons, however this question asks for how many WHOLE gallons you can get, so all you need to do is round down to fit your budget, leaving money for only 8 whole gallons.
WORK: ($27.00) / ($3.15) = 8.6 gallons
(g+b)*8
first add all of the people
and then multiply that by 8
