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2 years ago

Elijah spends 5 hours each week working out in a pool. This is twice the

Mathematics

2 answers:

Schach [20]2 years ago

4 0

Answer: he spends 2.5 hours in the weight room each week.

Step-by-step explanation: 2.5 multiplied by 2 (which is the twice amount of time spent working out in the pool) is 5.

So the answer is 2.5

forsale [732]2 years ago

3 0

Answer:the answer will be 70

Step-by-step explanation:5 times 14

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a park is 4 times as long as it is wide. if the distance around the park is 12.5 kilometers, what is the area of the park?

blsea [12.9K]

So, first, what are the two sides?

let's call then x and y

we know that 2(x+y)=12.5 (that's the distance around)

so that means that x+y=6.25 (I just divided both by 2)

now, x=4y (from "4 times as long as it is wide")

so we can substitute:

x+4x=6.25

5x=6.25

x=1.25

so one side, is 1.25 and the other will be 1.25*4=5

and for the area we multiply the two:

1.25*5=6.25 square kilometers, and this is the answer!

7 0

3 years ago

Read 2 more answers

Prove the following by induction. In each case, n is apositive integer.<br> 2^n ≤ 2^n+1 - 2^n-1 -1.

frutty [35]

<h2>Answer with explanation:</h2>

We are asked to prove by the method of mathematical induction that:

$2^n\leq 2^{n+1}-2^{n-1}-1$

where n is a positive integer.

Let us take n=1

then we have:

$2^1\leq 2^{1+1}-2^{1-1}-1\\\\i.e.\\\\2\leq 2^2-2^{0}-1\\\\i.e.\\2\leq 4-1-1\\\\i.e.\\\\2\leq 4-2\\\\i.e.\\\\2\leq 2$

Hence, the result is true for n=1.

Let us assume that the result is true for n=k

i.e.

$2^k\leq 2^{k+1}-2^{k-1}-1$

Now, we have to prove the result for n=k+1

i.e.

<u>To prove:</u> $2^{k+1}\leq 2^{(k+1)+1}-2^{(k+1)-1}-1$

Let us take n=k+1

Hence, we have:

$2^{k+1}=2^k\cdot 2\\\\i.e.\\\\2^{k+1}\leq 2\cdot (2^{k+1}-2^{k-1}-1)$

( Since, the result was true for n=k )

Hence, we have:

$2^{k+1}\leq 2^{k+1}\cdot 2-2^{k-1}\cdot 2-2\cdot 1\\\\i.e.\\\\2^{k+1}\leq 2^{(k+1)+1}-2^{k-1+1}-2\\\\i.e.\\\\2^{k+1}\leq 2^{(k+1)+1}-2^{(k+1)-1}-2$

Also, we know that:

$-2$

(

Since, for n=k+1 being a positive integer we have:

$2^{(k+1)+1}-2^{(k+1)-1}>0$ )

Hence, we have finally,

$2^{k+1}\leq 2^{(k+1)+1}-2^{(k+1)-1}-1$

Hence, the result holds true for n=k+1

Hence, we may infer that the result is true for all n belonging to positive integer.

i.e.

$2^n\leq 2^{n+1}-2^{n-1}-1$ where n is a positive integer.

6 0

3 years ago

Which expression is equivalent to 36a-27

sesenic [268]

This answer is a. Just do distributive property

5 0

3 years ago

Geometry help what is it will give brainliest

Lapatulllka [165]

For this problem, we can say that corresponding angles are congruent, or the same, this also means that their angle measures have to be the same. Then, our equations for our angles will be vertical angles, which means that they must equal each other. So we would then write our equation as 3x+20=4x+10 or 4x+10=3x+20. Then, to combine like terms, we will subtract 3x from both sides, resulting in x+10=20. Then we will subtract 10 from both sides, resulting in x=10.

5 0

3 years ago

Two urns each contain green balls and blue balls. Urn I contains 4 green balls and 6 blue balls, and Urn II contains 6 green bal

Morgarella [4.7K]

Urn 1 = 4 green balls and 6 blue balls, a total of 10 balls
Urn 2 = 6 green balls and 2 blue balls, a total of 8 balls.

Probability of blue balls:
Urn 1 : P = 6/10
Urn 2 : P = 2/8

Probability that both balls are blue:
6/10 * 2/8 = 6*2 / 10*8 = 12/80 = 6/40 = 3/20

Answer is B. 3/20

3 0

3 years ago