Number of new cars purchased in a city can be modeled by the equation

[gigi9]

Help ASAP please!

Can someone please show me how to do the 2 problems below? I really don't know how...Thanks
1)The number of new cars purchased in a city can be modeled by the equation C=22t^2+17tt+9933, where C is the number of new cars and t=0 corresponds to the number of new cars purchased in 1976. In what year will the number of new cars reach 38,000?

2)During the years 1992-1996, the average number of green grapes, G, sold by a large farmer's market can be modeled by
G= -11t^2+2.02t+41.09. The average number of red grapes, R, sold by the farmer's market can be modeled by R= .004t^2-.688t+79.06. Determine the model representing the number of grapes, N, sold from 1992-1996.

 

[KLscilevothma]

Here are some hints for you.

1)The number of new cars purchased in a city can be modeled by the equation C=22t^2+17t+9933, where C is the number of new cars and t=0 corresponds to the number of new cars purchased in 1976. In what year will the number of new cars reach 38,000?

We know C corresponds to the number of new cars purchased. You are given an equation showing the relation between C, number of cars purchased and t, where t=0 in 1976.
Can you use 38 000, which is the number of new cars sold in a particular year, to find out t? (Hint: you need to solve a quadratic equation)
After t is found, how can you relate t to the year 38000 cars are sold? (Hint, t=0 represents year 1976, how about t=1, t=2 and so on?)

2)During the years 1992-1996, the average number of green grapes, G, sold by a large farmer's market can be modeled by
G= -11t^2+2.02t+41.09. The average number of red grapes, R, sold by the farmer's market can be modeled by R= .004t^2-.688t+79.06. Determine the model representing the number of grapes, N, sold from 1992-1996.

You can use the way question 1 was asked as a reference.
Take t=1 represent year 1992.

In 1992, the average number of green grapes sold:
G₁₉₉₂= -11t^2+2.02t+41.09
the average number of red grapes sold:
R₁₉₉₂= .004t^2-.688t+79.06
total number of grapes sold in 1992 = G₁₉₉₂+R₁₉₉₂

In 1993, the average number of green grapes sold,
G₁₉₉₃ = -11(t+1)^2+2.02(t+1)+41.09
The average number of red grapes sold:
R₁₉₉₃= .004(t+1)^2-.688(t+1)+79.06.
Total number of grapes sold in 1993 = R₁₉₉₃+G₁₉₉₃

Can you continue from here?

 

[Hurkyl]

And we have a homework help forum specifically for, well, homework help.