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2 years ago

I NEED HELP WITH PRECALC PLEASE

Mathematics

2 answers:

alisha [4.7K]2 years ago

8 0

Answer: First question: D, Second question: A

Step-by-step explanation:

Note: I'm not so good at expanding so I'll just solve it :)

So this leaves either C or D

Apply the sum rule:

8-70=-62

The only one that gives a negative sum is D

For the second picture, the one you have chosen is correct

a1 = 3 and r = -5 so:

an = 3/5 * (-5)^n

Plugging in 8 for n (the first choice) we get the given term: -234,375

melamori03 [73]2 years ago

5 0

Answer:

(d) 2 +(-5) +(-12) +...
(a) a8

Step-by-step explanation:

Putting n = 0 and n = 1 into the expression being summed will show you which series is correct.

2 -7n for n=0 is 2 -7·0 = 2

2 -7n for n=1 is 2 -7·1 = -5

The series of the last choice (d) is correct.

The given sequence is exponential with a first term of 3 and a common ratio if -5. Then the n-th term is ...

an = 3(-5)^(n -1)

We want to find n for an = -234,375.

-234375 = 3(-5)^(n-1)

-78125 = (-5)^(n-1)

For n to be a real number, we must have n even. In that case, the value of n is equivalent to the value that is the solution to ...

78125 = 5^(n -1)

Taking logs of both sides, we get ...

log(78125) = (n -1)·log(5)

log(78125)/log(5) = n -1 . . . . . . . . . . . . divide by log(5)

n = 1 +log(78125)/log(5) = 1 +7 = 8 . . . add 1 and evaluate

-234,375 is the 8th term of the sequence.

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WILL MARK BRAINLIEST !!! PLEASE <br>find the length of PQ

mr_godi [17]

$\\ \rm\longmapsto L=\dfrac{\Theta}{180}\times \pi r$

$\\ \rm\longmapsto PQ=\dfrac{135}{180}\times 3.14(12)$

$\\ \rm\longmapsto PQ=\dfrac{3}{4}\times 37.68$

$\\ \rm\longmapsto PQ=\dfrac{113.04}{4}$

$\\ \rm\longmapsto PQ=28.3$

4 0

3 years ago

Jenna spends $15.04 at the store on notebooks and folders for school. Notebooks cost $4.85 each, and folders cost $0.89 each. Sh

cluponka [151]

Answer:

$\boxed{\text{2 notebooks and 6 folders}}$

Step-by-step explanation:

Let n = number of notebooks

and f = number of fodders

You have a system of two equations:

$\begin{cases}(1)& 4.85n + 0.89f = 15.04\\(2) & n+ f = 8\end{cases}\\\\$

$\begin{array}{lrcll}(3) & f & = & 8-n &\text{Subtracted n from each side of (2)}\\& 4.85n+0.89(8-n) & = & 15.04 &\text{Substituted (3) into (1)}\\& 4.85n+7.12-0.89n & = & 15.04 &\text{Distributed 0.89}\\& 3.96n+7.12 & = & 15.04 &\text{Combined like terms} \\& 3.96n & = & 7.92 & \text{Subtracted 7.12 from each side} \\(4) & n & = & 2 & \text{Divided each side by 3.96}\\& 2+ f & = & 8 & \text{Substituted (4) into (2)}\\& f & = & 6 &\text{Subtracted 2 from each side} \\\end{array}$

Jenna bought $\boxed{\textbf{two notebooks and six folders} }$ .

Check:

$\begin{array}{rclcrcl}4.85\times2+0.89\times6 & =& 15.04 & \qquad &2+6&=&8\\9.70+5.34 & = & 15.04 & \qquad &8&=&8\\15.04& = & 15.04 & & & & \\\end{array}$

OK.

4 0

3 years ago

PLEAS HELP I REALLY NEED HELP

blsea [12.9K]

Answer:

the first one in the picture

Step-by-step explanation:

8x8x8x8=4096

9x9x9x9=6561

4096x6561=26873856

72x72x72x72=26873856

5 0

3 years ago

You have 1 case of soap bars and there are 150 bars in a case. You use 300 bars of soap per day. How many cases do you need to o

diamong [38]

<span><u><em>Answer:</em></u>
14 cases

<u><em>Explanation:</em></u>
<u>First, we will need to find the number of cases needed per day:</u>
We know that one case includes 150 bars and that the daily consumption is 300 bars. To know the number of cases needed daily, we will use cross multiplication as follows:
1 case .............> 150 bars
?? cases .........> 300 bars
number of cases needed daily = </span> $\frac{300*1}{150}$ <span>
number of cases needed daily = 2 cases

<u>Then, we will get the number of cases needed weekly (7 days):</u>
We know that 2 cases are needed daily. To know the number of cases needed weekly (7 days), we will simply use cross multiplication as follows:
1 day .............> 2 cases
7 days ...........> ?? cases
number of cases needed weekly = </span> $\frac{7*2}{1}$ <span>
number of cases needed weekly = 14 cases

Hope this helps :)</span>

5 0

3 years ago

Maxwell’s vegetarian tacos require 34 tablespoons of chili powder for every 12 pounds of vegetables. How much chili powder will

Crazy boy [7]

Answer:

2 1/4

How?

Set up a proportion. The proportion will be teaspoons of chili powder over pound of vegetables.

Because of the above, the first proportion will be:

x is 3/4 and y is 1/2. Across from that proportion make another one

x is "n" because you're trying to figure out how much chili powder you need. y is 1 3/4.

Multiply 3/4 and 1 3/4, which is 9/16. Then, divide 9/16 and 1/2, which is 9/8. Simplify it to 1 1/8, and Maxwell will need 1 1/8 teaspoons of chili powder.

5 0

3 years ago