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3 years ago

Can someone explain how these equal 5 and -5 please

Mathematics

1 answer:

uysha [10]3 years ago

6 0

I'm not sure how you obtained -5 as your answer but this is the mathematical explanation. hope this helps!
${x}^{2} + 3x = 40 \\ {x}^{2} + 3x - 40 = 0 \\(x + 8)(x - 5) = 0 \\ x = - 8 \\ x = 5$

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faltersainse [42]

Answer:

Cost of bicycle. £403.50

His present savings. £265.90

Amount required. £137.60

Step-by-step explanation:

pls brain list I hope I helped

3 0

3 years ago

According to records from the last 50 years, there is a 2/3 chance of June temperatures being above 80 F. Azul needs to find the

dangina [55]

Here we shall use the binomial distribution formula to evaluate the probability:
let the probability that the temp will be above 80 be P(F)=2/3;
Probability that the temp will be below 80 be P(F')=1/3
thus,
The probability that the temp will be above 80 for 20 days for the month of June will be:
P(F)=n!/((n-x)!x!)p^xq^(n-x)
p=2/3 and q=1/3, n=30, x=20
plugging the values in the equation we obtain:
P(F)=30!/(10!*20!)*(2/3)^20*(1/3)^(30-20)
P(F)=0.153

6 0

3 years ago

Read 2 more answers

1, 1, 4, 8, 9 , ?, 16, 64

Elden [556K]

Answer:

Missing number ⇒ 27

Step-by-step explanation:

Given sequence is:

1, 1, 4, 8, 9 , ?, 16, 64

We need to find the missing number of the sequence.

Solution:

We can see the series consist numbers 1, 2, 3, 4, 5.. of power 2 and 3 each respectively. So, the series is $1^{2},1^{3},2^{2},2^{3},3^{2},3^{3}.....$ such that

$1 = 1^{2}\\1=1^{3}\\ 4=2^{2}\\\ 8=2^{3}\\\ 9=3^{2}\\\ 27=3^{3}------missing \ number\\\ 16=4^{2}\\\ 64=4^{3}$

Therefore, missing number is $3^{3}= 27$

8 0

3 years ago

Work out the lengths of sides a and b. Give your answers to 1 decimal place.

torisob [31]

Step-by-step explanation:

${a}^{2} = {8}^{2} + {5}^{2} \\ {a }^{2} = 64 + 25 \\ {a}^{2} = 89 \\ a = \sqrt{89} = 9.4 \: cm$

${17}^{2} = {12}^{2} + {b}^{2} \\ {b}^{2} = {17}^{2} - {12}^{2} \\ {b}^{2} = 289 - 144 \\ {b}^{2} = 145 \\ b = 12 \: cm$

3 0

3 years ago

in constructing a box and whisker plot from the data set below at which value would you draw the left and right side of the box

KatRina [158]

A box and whisker plot is a type of statistical graph that shows the median distributions of the data set. The box represents the data median and the medias of the quartiles. The whiskers represents the lines extended from the box to the lowest and the highest data.

Take this data as an example:
3.9, 4.1, 4.2, 4.3, 4.3, 4.4, 4.4, 4.4, 4.4, 4.5, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1
First, find the middle value. That would be the median. In this case, that would be 4.4. Let's denote this as Q₂ or Quartile 2. Now, take the group of data set before and after the median. These are:

3.9, 4.1, 4.2, 4.3, 4.3, 4.4, 4.4, 4.4

and

4.5, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1

The middle of the first data set is Q₁ = 4.3, while the middle of the second set is Q₃ = (4.7+4.8)/2 = 4.75

To construct the box and whisker plot, create line for the lowest value 3,9, Q₁, Q₂, Q₃ and the highest value, 4.4. The left side of the box would be Q₁, while the right side of the box is Q₃. The line in between is the media Q₂. The whiskers are the lines connecting the lowest to Q₁, and Q₃ to the highest on the other side. The resulting box and whisker plot is shown in the attached picture.

8 0

3 years ago