I did my khan academy assignments wrong and it’s due tomorrow and i’m stuck and freaking out, ive tried everything please help

Juli2301 [7.4K]

20 Answer: a₁ = 4

Step-by-step explanation:

$a_n=324,\ r=3,\ n=5\\\\a_n=a_1 \cdot r^{n-1}\\\\324=a_1\cdot 3^{5-1}\\\\\dfrac{324}{3^4}=a_1\\\\\dfrac{324}{81}=a_1\\\\\large\boxed{4}=a_1$

21 Answer: n = 13

Step-by-step explanation:

$a_n=\dfrac{1}{64},\ a_1=64,\ r=\dfrac{1}{2}\\\\a_n=a_1 \cdot r^{n-1}\\\\\dfrac{1}{64}=64\cdot \bigg(\dfrac{1}{2}\bigg)^{n-1}\\\\\dfrac{1}{64\cdot 64}=\bigg(\dfrac{1}{2}\bigg)^{n-1}\\\\\dfrac{1}{2^6\cdot 2^6}=\dfrac{1}{2^{n-1}}\\\\6+6=n-1\\\\\large\boxed{13}=n$

22 Answer: n = 5

Step-by-step explanation:

$a_n=48,\ a_1=1875\ r=\dfrac{2}{5}\\\\a_n=a_1 \cdot r^{n-1}\\\\48=1875\cdot \bigg(\dfrac{2}{5}\bigg)^{n-1}\\\\\dfrac{48}{1875}=\bigg(\dfrac{2}{5}\bigg)^{n-1}\\\\\dfrac{16}{625}=\bigg(\dfrac{2}{5}\bigg)^{n-1}}\\\\\bigg(\dfrac{2}{5}\bigg)^4=\bigg(\dfrac{2}{5}\bigg)^{n-1}}\\\\4=n-1\\\\\large\boxed{5}=n$

6 0

3 years ago

Read 2 more answers

A cell phone company has a basic monthly plan of $40 plus $0.45 for any minutes used over 700. Before receiving his statement, J

Serga [27]

Ok so we know he used over 700 because he was charged more than 40. Then we take the $8.10 and divide 0.45 into it. This then gives you 18 more minutes. Then add 18 to 700 and you get 718 min.

4 0

3 years ago

Solve i + j + t (3i - j) = -i + s (j) In the context of Vector Equations of a Line

Oksana_A [137]

Answer:

r = i + j + (-2/3)(3i - j)

Step-by-step explanation:

Vector Equation of a line - r = a + kb ; where r is the resultant vector of adding vector a and vector b and k is a constant

if a = i + j ; b = t(3i - j) and r = -i +s(j)

for this to be true all the vector components must be equal

summing i 's

i + 3ti = -i; then t = -2/3

j - tj = sj; then s = 1-t; substitue t; s=1+2/3 = 5/3

so r = i + j + (-2/3)(3i - j) which will symplify to -i + 5/3j

3 0

2 years ago

I need some help on this triangle similarity proof in Geometry!

AlladinOne [14]

I believe that this is correct if anything is unclear/blurry just ask and i will tell u what i wrote

8 0

3 years ago

The freshmen competed with the sophomores to see who could raise the most money by recycling. The appropriate design for testing

brilliants [131]

Answer:

Independent-samples t-test.

Step-by-step explanation:

We are looking for the appropriate design for testing the significance of the difference between the means.

Now, there is a parametric test known as the Independent Samples t Test and what this test does is that it compares the mean of two independent groups in order to find out whether there is statistical evidence that the related population mean is significantly different.

Thus, the test to be used here is Independent-samples t-test.

8 0

2 years ago