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2 years ago

What has she done wrong?

Mathematics

1 answer:

Strike441 [17]2 years ago

8 0

Answer:

see explanation

Step-by-step explanation:

Her error is in squaring (2y)²

She has (2y)² = 2y²

when it should be 2y × 2y = 4y²

Then

(2y)² = 6² + 8²

4y² = 36 + 64

4y² = 100 ( divide both sides by 4 )

y² = 25 ( take square root of both sides )

y = $\sqrt{25}$ = 5

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How to convert 3.248 repeating decimal with 48 repeating into a simplified fraction

Sonja [21]

Answer:

$x=\frac{536}{165}$

Step-by-step explanation:

Let X be the value of 3.2484848.... infinite times

Multiply by 100

$x=3.24848....\\100x = 324.8484.....$

Subtract to get

$100x-x = 324.8484...-3.248484....\\99x = 321.60\\x=\frac{321.6}{99} \\x=\frac{1072}{330} \\x=\frac{536}{165}$

Thus the number 3.248 repeating decimal with 48 repeating in fraction form is

$\frac{536}{165}$

7 0

3 years ago

Read 2 more answers

Use the rules of exponents to simplify the expressions. Match the expression with its equivalent value.

Lelechka [254]

Answer:

1) $\frac{(-2)^{-5}}{(-2)^{-10}}=-32$

2) $2^{-1}.2^{-4} = \frac{1}{32}$

3) $(-\frac{1}{2} )^3.(-\frac{1}{2} )^2=-\frac{1}{32}$

4) $\frac{2}{2^{-4}} = 32$

Step-by-step explanation:

1) $\frac{(-2)^{-5}}{(-2)^{-10}}$

Solving using exponent rule: $a^{-m}=\frac{1}{a^m}$

$\frac{(-2)^{-5}}{(-2)^{-10}}\\=(-2)^{-5+10}\\=(-2)^{5}\\=-32$

So, $\frac{(-2)^{-5}}{(-2)^{-10}}=-32$

2) $2^{-1}.2^{-4}$

Using the exponent rule: $a^m.a^n=a^{m+n}$

We have:

$2^{-1}.2^{-4}\\=2^{-1-4}\\=2^{-5}$

We also know that: $a^{-m}=\frac{1}{a^m}$

Using this rule:

$2^{-5}\\=\frac{1}{2^5}\\=\frac{1}{32}$

So, $2^{-1}.2^{-4} = \frac{1}{32}$

3) $(-\frac{1}{2} )^3.(-\frac{1}{2} )^2$

Solving:

$(-\frac{1}{2} )^3.(-\frac{1}{2} )^2\\=(-\frac{1}{8} ).(\frac{1}{4} )\\=-\frac{1}{32}$

So, $(-\frac{1}{2} )^3.(-\frac{1}{2} )^2=-\frac{1}{32}$

4) $\frac{2}{2^{-4}}$

We know that: $a^{-m}=\frac{1}{a^m}$

$\frac{2}{2^{-4}}\\=2\times 2^4\\=2(16)\\=32$

So, $\frac{2}{2^{-4}} = 32$

3 0

3 years ago

Drake's Drugstore is getting ready for the upcoming summer season. The manager of the store wants to

patriot [66]

Answer:

22222222222222222 not 3 and not 1

Step-by-step explanation:

5 0

3 years ago

Solve V- E = 2 for E; E =<br> A.) V - 2 <br> B.) V + 2 <br> C.) - V - 2 <br> D.) - V + 2

zhuklara [117]

Add v to both sides: -E=2+V
Divide both sides by -1: E= -2-V

Answer: -V-2

3 0

3 years ago

Sam needs to make a long-distance call from a pay phone. With his prepaid phone card, he will be charged $1.00 to connect and $0

Mademuasel [1]

Answer: The required system of equations representing the given situation is

$y=1+0.5x\\\\y=3+0.25x$

Step-by-step explanation: Given that Sam needs to make a long-distance call from a pay phone.

We are to write a system to represent the situation.

Let x represent the number of minutes Sam talked on the phone and y represents the total amount that he paid for the call.

According to the given information,

with prepaid phone card, Sam will be charged $1.00 to connect and $0.50 per minute.

So, the equation representing this situation is

$y=1+0.5x~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)$

Also, if Sam places a collect call with the operator he will be charged $3.00 to connect and $0.25 per minute.

So, the equation representing this situation is

$y=3+0.25x~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(ii)$

Thus, the required system of equations representing the given situation is

$y=1+0.5x\\\\y=3+0.25x$

3 0

2 years ago