$= \pi {r}^{2} h \\ \\ = 3.14 \times ( {3.25)}^{2} \times 10 \\ \\ = 3.14 \times 10.5625 \times 10 \\ \\ = 331.6625 {cm}^{3} \\ \\ \approx \: 331.66 \: {cm}^{3}$

4 0

3 years ago

Which expression is equivalent to 60 Σ n=1 (2n − 1)2 ? Check all that apply.

Hunter-Best [27]

9514 1404 393

Answer:

B, D

Step-by-step explanation:

The quadratic expands to ...

(2n -1)² = (2n)² +2(2n)(-1) +(-1)² = 4n² -4n +1

The coefficients can be factored out of the sum, so ...

∑(4n²) = 4∑n² for example

The sum of 60 ones is 60:

$\displaystyle\sum_{n=1}^{60}{1}=1+1+1+\dots+1=60$

So, the sum can be written as ...

$\displaystyle\sum_{n=1}^{60}{(2n-1)^2}\\\\=\boxed{4\sum_{n=1}^{60}{n^2}-4\sum_{n=1}^{60}{n}+\sum_{n=1}^{60}{1}}\\\\=\boxed{4\sum_{n=1}^{60}{n^2}-4\sum_{n=1}^{60}{n}+60}$

_____

It appears that the key to choosing the correct answers is paying attention to signs.

7 0

3 years ago

Read 2 more answers

Turn 40% into a whole number

makvit [3.9K]

Answer:

as a decimal it is 0.4 as a fraction it is 2/5

6 0

3 years ago

Read 2 more answers