If x square plus y square is equals 80 and xy is equals 12,find the value of (x-y)square

there are nickels, dimes, and quarters in a piggy bank. altogether, the coins are worth $3.65. the number of dimes is three time

hoa [83]

This question is solved using a system of equations, and doing this, we get that: There are 9 quarters, 4 nickels and 12 dimes.

I am going to say that:

x is the number of nickels.

y is the number of dimes.

z is the number of quarters.

In all, they are worth $3.65.

A nickel is worth $0.05, a dime is worth $0.1 and a quarter is worth $0.25, so:

$0.05x + 0.1y + 0.25z = 3.65$

Dimes: 3 times greater than nickels:

This means that:

$y = 3x$

Quarters: One greater than double the number of nickels:

This means that:

$z = 2x + 1$

Value of x:

We have y and z as function of x, so we can replace into the equation and find the value of x, so:

$0.05x + 0.1y + 0.25z = 3.65$

$0.05x + 0.1(3x) + 0.25(2x+1) = 3.65$

$0.05x + 0.3x + 0.5x + 0.25 = 3.65$

$0.85x = 3.4$

$x = \frac{3.4}{0.85}$

$x = 4$

y and z:

$y = 3x = 3(4) = 12$

$z = 2x + 1 = 2(4) + 1 = 9$

There are 9 quarters, 4 nickels and 12 dimes.

A similar question is found at brainly.com/question/17096268

4 0

2 years ago

As of April 2006, roughly 50 million web domain names were registered (e.g., ). How many domain names consisting of just two let

Furkat [3]

Answer:

a) 676, 1296

b) 17576, 46656

c) 456976, 1679616

Step-by-step explanation:

firstly we know that there are 26 letters in the alphabet.

there are 26 ways of choosing the first character and 26 ways choosing the second character,

Therefore, the possible number of domains with two leeter is;

n = 26²

= 26 × 26

= 676

now when the digits are allowed, there are 26 + 10 = 36 characters to be used in total

therefore the possible number of domains with two characters is;

n = 36²

= 36 × 36

= 1296

b)

there are 26 ways of choosing each character

therefore, the possible number of domains with three letters is

n = 26³

= 26 × 26 × 26

= 17576

when the digits are allowed, there are 26 + 10 = 36 characters to be used in total

therefore , the possible number of domains with three characters is;

n = 36³

= 36 × 36 × 36

= 46656

c)

there are 26 ways of choosing each character, therefore the possible number of domains with four letters is;

n = 26⁴

n = 26 × 26 × 26 × 26

n = 456976

when the digits are allowed, there are 26 + 10 = 36 characters to be used in total

therefore, the possible number of domains with four characters is;

n = 36⁴

n = 36 × 36 × 36 × 36

= 1679616

7 0

2 years ago

A small town had a population 960 people last year. The population grew to 1200 people this year. By what percentage did the pop

Rufina [12.5K]

Answer:

25%

Step-by-step explanation:

1200/960 = 1.25

So it grew by 25%

3 0

2 years ago

Evaluate the expression 3 ⋅ 2^t , when t=1. *

lisov135 [29]

Answer:

6

Step-by-step explanation:

3 ⋅ 2^t

Let t=1

3 ⋅ 2^1

Exponents first

3 * 2

6

8 0

2 years ago

The 90% confidence interval for the mean one-way commuting time in New York City is

Zinaida [17]

Answer:

95% provides more information

Step-by-step explanation:

The confidence interval is obtained by using the relation :

Xbar ± Zcritical * σ/√n

(Xbar - (Zcritical * σ/√n)) = 5.22 - - - (1)

(Xbar + (Zcritical * σ/√n)) = 5.98 - - (2)

Adding (1) and (2)

2xbar = 5.22 + 5.98

2xbar = 11.2

xbar = 11.2 / 2 = 5.6

Margin of Error :

Xbar - lower C.I = Zcritical * σ/√n

Zcritical at 90% = 1.645

5.6 - 5.22 = 1.645 * (σ/√n)

0.38 = 1.645 * (σ/√n)

(σ/√n) = 0.38 / 1.645 = 0.231

Therefore, using the se parameters to construct at 95%

Zcritical at 95% = 1.96

Margin of Error = Zcritical * σ/√n

Margin of Error = 1.96 * 0.231 = 0.45276

C.I = xbar ± margin of error

C. I = 5.6 ± 0.45276

C.I = (5.6 - 0.45276) ; (5.6 + 0.45276)

C. I = (5.147 ; 6.053)

Hence, 95% confidence interval provides more information as it is wider.

3 0

2 years ago