1. ## solve

I have figured out the solutions to these problems partially, but some parts of the problems i can't just get em.... thanks for your help!!!!!!!!!!!!

1)A science museum is oging to put an outdoor restaurant along one wall of the museum. The restaurant space will be rectangular. Assume the museum would prefer to mzximize the area for the restaurant.
a.suppose there is 120 feet of fencing avaliable for the three sides that require fencing. How long will the longest side of the restaurant be?
b.what is the maxium area? (this is the problem that i have no clue)

2)A local health official has determined that the function y= -3/640x^2 + 3/40x modles the probability that a randomly chosen individual in the community will get the flu xdays after the firs reported case.
A) Write the function in vertex form.(which i got: y=-3/640(x-8)^2+3/10 ) Is it right?
B)How many days after the first reported case is the risk greatest that an individual will become infected?

3)A park planner has sketched a rectangular park in the first quadrant of a coordinate grid. Two sides of the park lie on the x and y axes. A trapezoidal flower bed will be bounded by the line y=x+7, the x axis and the vertical lines x=1 and x=a, where a>1. The area A of the trapezoid is modeled by A=1/2a^2+7a-15/2. Assume that lengths along the zxes are measured in meters. For what value of a will be the trapezoid have an area of 25 meters? Use the Quadratic formula to find the answer.

I rally need help on this

2. He;llo, jjkins!

#3 is a truly silly problem . . . way too much information!
I'll distill it to its very essence . . .

3) Given: . $A \:=\:\frac{1}{2}x^2 + 7x - \frac{15}{2}$

For what positive value of $x$ is $A \:=\:25$ ?

We have: . $\frac{1}{2}x^2 + 7x - \frac{15}{2}\:=\:25$

Now solve for $x$ . . .