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3 years ago

A rectangle is 2 √7 feet wide and 3 √7 feet long. What is the area, in square feet, of

Mathematics

1 answer:

Flura [38]3 years ago

3 0

Answer:

$42ft^{2}$

Step-by-step explanation:

$2\sqrt{7}$ × $3\sqrt{7}$

Multiply the numbers outside the root and inside the root.

$2x3=6$ $7x7=49$

$6\sqrt{49}$

Simplify whats under the root

$\sqrt{49} = 7$

$6$ × $7=42$

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In a flower garden, there are 4 tulips for every 9 daisies. If there are 24 tulips, how many daisies are there?

Paul [167]

Answer:

54 daisies

Step-by-step explanation:

4 tulips : 9 daisies

24 tulips : ?

(24 × 9) ÷ 4 = 54 daises

3 0

3 years ago

15 points!!! GEOMETRY help please!! Questions attached!

dolphi86 [110]

3. Look at the picture.

We have the right angle triangle. We know the sum of measures of angles in triangle is equal 180°. Therefore:

$x^o+90^o+43^o=180^o\\\\x^o+133^o=180^o\ \ \ |-133^o\\\\x^o=47^o$

$Answer:\ \boxed{47^o}$

4.
Look at the picture.

Use Pythagorean theorem:

$x^2+14^2=(10+x)^2\\\\x^2+196=10^2+2\cdot10\cdot x+x^2\ \ \ \ |-x^2\\\\196=100+20x\ \ \ |-100\\\\20x=96\ \ \ |:20\\\\x=4.8$

$Used:\ (a+b)^2=a^2+2ab+b^2$

$Answer:\ \boxed{4.8\ units}$

5.
TRUE: 1; 2; 4

6.
We find a slope of the line OP:

$m=\dfrac{y_2-y_1}{x_2-x_1}\\\\O(2;\ 6)\to x_1=2;\ y_1=6\\\\P(4;\ 3)\to x_2=4;\ y_2=3\\\\m=\dfrac{3-6}{4-2}=\dfrac{-3}{2}$

We have: $OP:\ y=-\dfrac{3}{2}x+b$

Now, we must find the slope of the line perpendicular to the line OP.
We know:

$k:y=m_1x+b;\ l:y=m_2x+c\\\\k\ \perp\ l\iff m_1m_2=-1$

therefore

$-\dfrac{3}{2}m_2=-1\ \ \ |\cdot\left(-\dfrac{2}{3}\right)\\\\m_2=\dfrac{2}{3}$

So. We have the answer! :)

$Answer:\ \boxed{y=\dfrac{2}{3}x+\dfrac{1}{3}}$

6 0

3 years ago

The Johnson family went to the Olive Garden. The total was $73.28. If they leave a 20% tip, how much

zlopas [31]

Answer:

14.6

Explanation:

It's pretty simple if you use a calculator, have a nice day and good luck with your work! <3

3 0

3 years ago

Please, help thanks! I would like an explanation how to do it too, IF you dont mind.

Aneli [31]

Answer:

Phoebe has £180, Andy has £60, and Polly has £30.

Step-by-step explanation:

Ok, to start of let's establish some variables! We'll give Phoebe the variable "p", Andy the variable "a", and Polly the variable "o". By giving each person a variable we can create an equation and solve for it!

So, what do we know?

Well we know the following information...

p + a + o = 270

(Phoebe + Andy + Polly = £270)

p = 3a

(Phoebe = 3 times more than Andy)

a = 2o

(Andy = 2 times more than Polly)

To be able to solve this equation we have to solve for just one variable first.The only one we can use is "o" for Polly!

3(2o) + 2o + o = 270

6o + 2o + o = 270 (Distribute 3 to get like terms)

9o = 270 (Combine like terms [6+2+1])

o = 30 (Divide by 9 on both sides to get "o" by itself)

Now that we have how much Polly has, we have to solve for Andy and Phoebe. (To do this we will input our value, 30, where our variable is "o")

Andy

a = 2(30) (Input term)

a = 60 (Multiply by 2 to get final answer)

(Since we now know what Andy has we can input 60 into our "a" variable to solve for Phoebe)

Phoebe

p = 3(60) (Input term)

p = 180 (Multiply by 3 to get final answer)

Now! Just to check we are going to input our variables into our original equation to be sure we have the right variables.

p + a + o = 270

180 + 60 + 30 = 270!!

Hope this Helps! :)

Have any questions? Ask below in the comments and I will try my best to answer.

-SGO

4 0

3 years ago

(3 marks) A certain type of storage battery lasts, on average, 3.0 years with a standard deviation of 0.5 year. The battery live

Ksenya-84 [330]

Answer:

0.8041 = 80.41% probability that a given battery will last between 2.3 and 3.6 years

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

A certain type of storage battery lasts, on average, 3.0 years with a standard deviation of 0.5 year

This means that $\mu = 3, \sigma = 0.5$