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3 years ago

Evaluate √81/√9 help lolll

Mathematics

2 answers:

TEA [102]3 years ago

8 0

Answer:

Step-by-step explanation:

$\frac{\sqrt{81} }{\sqrt{9} }$

Find the square root of the numerator and denominator

The square root of 81 is 9 (9*9=81)

The square root of 9 is 3 (3*3=9)

$\frac{9}{3}$

Divide

Hope this helps! :)

just olya [345]3 years ago

4 0

Answer:

Step-by-step explanation:

$\sqrt{81}=9\\\sqrt{9}=3\\therefore 9x3=27$

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2а +3Ь — 5 b = a – 5

schepotkina [342]

Answer:

a= -2b

Step-by-step explanation:

math.

8 0

3 years ago

A scientist changes the temperature of a solution at a rate of

Anton [14]

Answer: A 9 min

Step-by-step explanation: 54/6=9

-6-6-6-6-6-6-6-6-6=-54

3 0

3 years ago

Sally gets a cup of coffee and a muffin every day for breakfast from one of the many coffee shops in her neighborhood. She picks

aniked [119]

Answer:

A. Mean of the amount Sally spends on breakfast daily = $ 3.90

Standard deviation of the amount Sally spends on breakfast daily = $ 0.34 (rounding to the next cent)

B. Mean of the amount Sally spends on breakfast weekly = $ 27.30

Standard deviation of the amount Sally spends on breakfast weekly = $ 0.89 (rounding to the next cent)

Step-by-step explanation:

1. Let's review the information given to us to answer the question correctly:

Average price of a cup of coffee = $ 1.40

Standard deviation = $0.30

Average price of a muffin = $ 2.50

Standard deviation = $ 0.15

The two prices are independent of each other

2. What is the mean and standard deviation of the amount Sally spends on breakfast daily?

Let's recall that:

1. The mean of the sum of two independent variables is the sum of their means.

2. The variance of the sum of two independent variables is equal to the sum of their variances.

Therefore,

Mean of the amount Sally spends on breakfast daily = Average price of a cup of coffee + Average price of a muffin

Replacing with the values we know:

Mean of the amount Sally spends on breakfast daily = 1.40 + 2.50

Mean of the amount Sally spends on breakfast daily = $ 3.90

Variance of the amount Sally spends on breakfast daily = Variance of the price of a cup of coffee + Variance of the price of a muffin

Replacing with the values we know:

Variance of the amount Sally spends on breakfast daily = 0.30² + 0.15²

Variance of the amount Sally spends on breakfast daily = 0.1125

Standard deviation of the amount Sally spends on breakfast daily = √0.1125

Standard deviation of the amount Sally spends on breakfast daily = $ 0.34 (rounding to the next cent)

3. What is the mean and standard deviation of the amount she spends on breakfast weekly (7 days)?

Mean of the amount Sally spends on breakfast weekly = 7 * Mean of the amount Sally spends on breakfast daily

Mean of the amount Sally spends on breakfast weekly = 7 * 3.90

Mean of the amount Sally spends on breakfast weekly = $ 27.30

Variance of the amount Sally spends on breakfast weekly = 7 * Variance of the amount Sally spends on breakfast daily

Variance of the amount Sally spends on breakfast weekly = 7 * 0.1125

Variance of the amount Sally spends on breakfast weekly = 0.7875

Standard deviation of the amount Sally spends on breakfast weekly = √0.7875

Standard deviation of the amount Sally spends on breakfast weekly = $ 0.89 (rounding to the next cent)

3 0

4 years ago

Determine whether the graphs of the two equations are perpendicular x-7y=4 and 21x+3y=11

Sveta_85 [38]

Step-by-step explanation:

when multiplied together, the gradients of the 2 graphs should equal -1 (of they are perpendicular).

x-7y=4

-7y= -x + 4

y= -1/7 x + 4/7

21x+ 3y=11

3y=-21x+11

y=-21/3 x + 11/3

-21/3 * -1/7 = 1

when multipled together, the 2 gradients dont equal -1 therefore they are not perpendicular

unless I've made a mistake with the signs at some point haha

3 0

3 years ago

3w + 6 - 4W + 3b + 2 + 2b =

stellarik [79]

Answer:

A) 5b - w + 8

Step-by-step explanation:

Hope it helps you :)

4 0

3 years ago