DELL LAPTOP WITH A RETAIL PRICE OF $525 FOR ONLY $393.75 what is the percent of change

4x-5y+2z=-3<br> 6x+4y+9z=8<br> 11x-2y-z=7

Nutka1998 [239]

Answer:

thank you i need that

Step-by-step explanation:

4 0

4 years ago

Alex and Peter win some money and share it in the ratio 3:5. Alex gets £33. How much did Peter get?

IgorLugansk [536]

Answer:

Step-by-step explanation:

Set it up as fractions, Alex over Peter.

3/5 : 33/x Let x represent Peter's amount. Now find out: how do you get from 3 to 33? What times 3 equals 33? 11

What you do on the top, you must do on the bottom. If 3 times 11 equals 33, then 5 times 11 equals x. 5 times 11 equals 55, so x equals 55.

Peter will get 55. Don't forget the pound symbol.

5 0

3 years ago

Mariano delivers newspapers. He always puts 3/4 of his weekly earnings in his savings account and then divides the rest equally

lesya [120]

Answer:

a. Fraction of earnings that Mariano put into each piggy bank is 1/12

b. Mariano earns $28.8

Step-by-step explanation:

Mariano divides his earning in a saving account and 3 piggy banks.

First , we have to know the fraction that we divide in the 3 piggy banks.

Piggy banks =Total earning-Saving account

Saving account 3/4,

Total earning is 1

to rest both term we have to get the same denominator , so we can say that the total earning is 4/4

Piggy banks =4/4-3/4=( 4-3)/4=1/4

Piggy banks =1/4

Each piggy bank will be 1/3 of that 1/4

1/3 x 1/4=

For fraction multiplication, multiply the numerators and then multiply the denominators to get

1×1/3×4=1/12

This fraction cannot be reduced.

b. Mariano adds $2.40

1/12 is 2.40

total earning is ?

We use cross-multiplication

a/b=c/d replacing (1/12)/2.40 = 1/ ?

So, the total earning (?) is 1 x 2.40/ (1/12)

= 2.40 x 12=$28.8

6 0

3 years ago

A student takes a multiple-choice test that has 11 questions. Each question has five choices. The student guesses randomly at ea

marissa [1.9K]

Answer:

a) P(6) = 0.0097

b) P(More than 3) = 0.1611

Step-by-step explanation:

For each question, there are only two possible outcomes. Either it is guessed correctly, or it is not. Questions are independent of each other. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

A student takes a multiple-choice test that has 11 questions.

This means that $n = 11$

Each question has five choices.

This means that $p = \frac{1}{5} = 0.2$

(a) Find P (6)

This is P(X = 6).

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 6) = C_{11,6}.(0.2)^{6}.(0.8)^{5} = 0.0097$

P(6) = 0.0097

(b) Find P (More than 3).

Either P is 3 or less, or it is more than three. The sum of the probabilities of these outcomes is 1. So

$P(X \leq 3) + P(X > 3) = 1$

We want P(X > 3). So

$P(X > 3) = 1 - P(X \leq 3)$

In which

$P(X \leq 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{11,0}.(0.2)^{0}.(0.8)^{11} = 0.0859$

$P(X = 1) = C_{11,1}.(0.2)^{1}.(0.8)^{10} = 0.2362$

$P(X = 2) = C_{11,2}.(0.2)^{2}.(0.8)^{9} = 0.2953$

$P(X = 3) = C_{11,3}.(0.2)^{3}.(0.8)^{8} = 0.2215$

$P(X \leq 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) = 0.0859 + 0.2362 + 0.2953 + 0.2215 = 0.8389$

Then

$P(X > 3) = 1 - P(X \leq 3) = 1 - 0.8389 = 0.1611$

P(More than 3) = 0.1611

8 0

4 years ago

#11 and #13 geometry help please help need work shown as well !!

Trava [24]

Answer: In diagram (11) X = 30 degrees and Y = 60 degrees

In diagram (13) X = 20.55 degrees and Y = 69.45 degrees

Step-by-step explanation: What we have are two right angled triangles with two sides given in each case, therefore we can calculate the two unknown angles (since the third angle equals 90 degrees).

For the second triangle (number 13) we shall use Y as the reference angle. That means we have an opposite (the side facing the reference angle) which is 24 and we have an adjacent (the side that lies between the right angle and the reference angle) which is 9. Hence,

Tan Y = opposite/adjacent

Tan Y = 24/9

Tan Y = 2.6667

Checking with your calculator or table of values, 2.6667 = 69.45

Having two angles, which are 90 and 69.45, the third angle X can be computed as

X = 180 - (90 + 69.45)

Sum of angles in a triangle equals 180

X = 180 - 159.45

X = 20.55 and Y = 69.45

For the first triangle (number 11) we shall use X as the reference angle. We have two sides, the opposite (the side facing the reference angle) which is 3, and the hypotenuse (side facing the right angle) which is 6. Hence,

Sin X = opposite/hypotenuse

Sin X = 3/6

Sin X = 0.5000

Checking with your calculator or table of values,

X = 30 degrees.

Also, now that we have two angles we can easily compute the third angle as follows

Y = 180 - (90 + 30)

Sum of angles in a triangle equals 180

Y = 180 - 120

Y = 60

X = 30 and Y = 60

4 0

3 years ago