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3 years ago

If u=18, x=−10, and y=8 what is the value of u+xy?

Mathematics

1 answer:

Oksanka [162]3 years ago

8 0

Answer:

-62

Step-by-step explanation:

Step 1: Define

u = 18

x = -10

y = 8

u + xy

Step 2: Substitute

18 + -10(8)

Step 3: Evaluate

18 - 80

-62

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Lacey and richens decide to connect their two machines so that lacey’s output becomes richens ‘ input. If 3 is the initial, what

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Answer:

Step-by-step explanation:

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2 years ago

How would the expression x2 +8 be rewritten using Sum of Cubes?

Nadusha1986 [10]

Answer:

$x^3+8=(x+2)(x^2-2x+4)$

So if they meant $x^3+8$ then the answer is:

$(x+2)(x^2-2x+4)$ .

The choice this corresponds to is A.

Step-by-step explanation:

The sum of cubes formula for factoring or expanding:

$a^3+b^3=(a+b)(a^2-ab+b^2)$

You have I'm assuming they meant:

$x^3+8$ .

Compare $x^3+8$ to $a^3+b^3$ .

You should see in place of $a$ you have $x$ .

You should also see in place of $b$ you have $2$ .

$a^3+b^3=(a+b)(a^2-ab+b^2)$

$x^3+8$

$x^3+2^3$

$x^3+2^3=(x+2)(x^2-2x+2^2)$

$x^3+8=(x+2)(x^2-2x+4)$

Let's check it for fun.

So we are going to use the distributive property.

We are going to distribute all the terms in the first ( ) to all the terms in the second ( ).

$x(x^2-2x+4)$ + $2(x^2-2x+4)$

$x^3-2x^2+4x$ + $2x^2-4x+8$

Combine like terms:

$x^3-2x^2+2x^2+4x-4x+8$

Simplify the grouping of like terms:

$x^3+0x^2+0x+8$

0 times anything is 0:

$x^3+8$

8 0

3 years ago

Ecuaciones <br> 5/3+2/4x=1/2

liubo4ka [24]

I don't get what you meant

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3 years ago

Sally spins a fair spinner numbered 1 - 5 and rolls a fair dice.

Elza [17]

Answer: Probability of obtaining a multiple of 3 and a factor of 10 is given by

$\frac{1}{10}$

Step-by-step explanation:

Since we have given that

There is a fair spinner numbered 1-5 and a fair dice

Total number of outcomes of fair spinner = 5

Total number of outcomes of a fair dice = 6

Let Event A: Getting a multiple of 3 on a spinner

Event B: Getting a factor of 10 on a fair dice

The possible outcomes of multiple of 3 on a spinner is

$3$

The possible outcomes of factor of 10 on a fair dice are

$1,2,5$

So,

$P(A)=\frac{1}{5}$

and

$P(B)=\frac{3}{6}=\frac{1}{2}$

Since A and B are independent events so,

$P(A\ and\ B)=P(A).P(B)\\\\P(A\ and\ B)=\frac{1}{5}\times \frac{1}{2}\\\\P(A\ and\ B)=\frac{1}{10}$

Hence, Probability of obtaining a multiple of 3 and a factor of 10 is given by

$\frac{1}{10}$

4 0

2 years ago

Data were collected on the amount spent by 64 customers for lunch at a major Houston restaurant. These data are contained in the

galina1969 [7]

Answer:

a. The margin of error is 2.29.

b. 19.23 to 23.81

Step-by-step explanation:

The sample size is n=64.

We start by calculating the sample mean and standard deviation with the following formulas:

$M=\dfrac{1}{n}\sum_{i=1}^n\,x_i\\\\\\s=\sqrt{\dfrac{1}{n-1}\sum_{i=1}^n\,(x_i-M)^2}$

The sample mean is M=21.52.

The sample standard deviation is s=6.89.

We have to calculate a 99% confidence interval for the mean.

The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.

When σ is not known, s divided by the square root of N is used as an estimate of σM:

$s_M=\dfrac{s}{\sqrt{N}}=\dfrac{6.89}{\sqrt{64}}=\dfrac{6.89}{8}=0.861$

The degrees of freedom for this sample size are:

$df=n-1=64-1=63$

The t-value for a 99% confidence interval and 63 degrees of freedom is t=2.656.

The margin of error (MOE) can be calculated as:

$MOE=t\cdot s_M=2.656 \cdot 0.861=2.29$

Then, the lower and upper bounds of the confidence interval are:

LL=M-t \cdot s_M = 21.52-2.29=19.23\\\\UL=M+t \cdot s_M = 21.52+2.29=23.81

The 99% confidence interval for the mean is (19.23, 23.81).

5 0

3 years ago