Answer:
1.97 ounces
Step-by-step explanation:
-The exponential decay function is given by the formula:

Given that the half-life is 4 days, we can substitute in the formula to solve the rate of decay for a single half-life:

#Since, 1 week has 7 days, 3 weeks is a 21-day period, thus, t=21.
#We substitute and solve for the amount remaining after 21days of decay:

Hence, the amount remaining after 3 weeks of decays is approximately 1.97 ounces
Shorter side: 130ft
longer side: 260ft
greatest possible area: 33800ft^2
basically get the equations for area and perimeter which will be
A: lw (length x width)
P: l + 2w
Substitute them into eachother and you get the equation:
-2w^2+520w = A
find the vertex of this parabola which will give you the greatest width which is 130m
Then u can find length and area from this width
When they say quotient, they want a fraction, so the answer for that would be

and the decimal form of that would be 0.6. You can get that from dividing 6 by 10 and solving with long division.
first off, let's convert the mixed fraction to improper fraction and then proceed, let's notice that by PEMDAS or order of operations, the multiplication is done first, and then any sums.
![\stackrel{mixed}{1\frac{7}{8}}\implies \cfrac{1\cdot 8+7}{8}\implies \stackrel{improper}{\cfrac{15}{8}} \\\\[-0.35em] ~\dotfill\\\\ -\cfrac{3}{4}~~ + ~~\cfrac{15}{8} \div \cfrac{1}{2}\implies -\cfrac{3}{4}~~ + ~~\cfrac{15}{8} \cdot \cfrac{2}{1}\implies -\cfrac{3}{4}~~ + ~~\cfrac{15}{4} \\\\\\ \cfrac{-3+15}{4}\implies \cfrac{12}{4}\implies 3](https://tex.z-dn.net/?f=%5Cstackrel%7Bmixed%7D%7B1%5Cfrac%7B7%7D%7B8%7D%7D%5Cimplies%20%5Ccfrac%7B1%5Ccdot%208%2B7%7D%7B8%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B15%7D%7B8%7D%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B8%7D%20%5Cdiv%20%5Ccfrac%7B1%7D%7B2%7D%5Cimplies%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B8%7D%20%5Ccdot%20%5Ccfrac%7B2%7D%7B1%7D%5Cimplies%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B4%7D%20%5C%5C%5C%5C%5C%5C%20%5Ccfrac%7B-3%2B15%7D%7B4%7D%5Cimplies%20%5Ccfrac%7B12%7D%7B4%7D%5Cimplies%203)