1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Yuri [45]
3 years ago
7

Please teach me on how to answer this question. (addmath question)

Mathematics
1 answer:
arsen [322]3 years ago
5 0

We know that \overline{x}=8 so:

\overline{x}=8\\\\\\\dfrac{\sum\limits_{k=1}^7\,x_k}{7}=8\qquad|\cdot7\\\\\\ \boxed{\sum\limits_{k=1}^7\,x_k=56}

We want to calculate:

\sum\limits_{k=1}^7\,\big(2x_k-3\big)^2=\sum\limits_{k=1}^7\,\big(4x_k^2-12x_k+9\big)=\\\\\\=\sum\limits_{k=1}^7\,4x_k^2-\sum\limits_{k=1}^7\,\big12x_k+\sum\limits_{k=1}^7\,9=4\sum\limits_{k=1}^7\,x_k^2-12\sum\limits_{k=1}^7\,x_k+\sum\limits_{k=1}^7\,9=\\\\\\=4\cdot672-12\cdot56+7\cdot9=2688-672+63=\boxed{2079}

You might be interested in
Does anyone know how to substitute -2 into this equation -2x + ( 12 - 9 ) = 2 + 9 + -2x
alexandr1967 [171]

Answer:

-2(-2) + (12-9) = 2 + 9 + -2(-2)

Step-by-step explanation:

6 0
3 years ago
Garrett is 64 inches how many centimeters tall is he round your answer to the nearest tenth of a centimeter. 1 in.=2.54cm
Marysya12 [62]
To answer this we just need to convert by multiplying. Lets do it:-

1 in = 2.54 cm

64 × 2.54 = 162.56
64 in = 162.56 cm.  

To round 162.56 to the nearest tenth we will look at 162.56. Since this number is 5 we will round to the next number which will make it 162.60.

So, 64 in = 162.56 cm rounded to the nearest tenth is 162.60.

Hope I helped ya!! 
7 0
3 years ago
Read 2 more answers
Simplify the problem thank you
NikAS [45]

Given the expression:

\displaystyle \large{ \sqrt[3]{ - 125} }

Definition:

\displaystyle \large{ y  = \begin{cases}   \pm \sqrt[n]{x}  \longrightarrow n  = (2,4,6,8,...)  \:  \: (x \geqslant 0) \\   \sqrt[n]{x}\longrightarrow n = (1,3,5,7,...) \:  \: (x \in \R) \end{cases}}

First, factor the -125. -125 comes from (-5)×(-5)×(-5) or (-5)^3.

\displaystyle \large{ \sqrt[3]{ ( - 5) \times ( - 5) \times ( - 5)} }

Because if (-5)^2 = 25 then 25×(-5) again will be -125.

Since this is the cube root, we have to pull out 3 terms in one. There are 3 fives that we can take off and therefore,

\displaystyle \large \boxed{ - 5}

5 0
3 years ago
Read 2 more answers
I need to find The original slope and perpendicular slope pleaseee
suter [353]

Answer:

OG slope is 1, perpendicular slope is -1

Step-by-step explanation:

rise over run is 1/1, perpendicular slopes are the reciprocoal, or opposite slope, so -1

6 0
3 years ago
I think it’s a or b but I’m thinking it’s a am I correct?
Aleonysh [2.5K]
Yes you are correct it is A
7 0
3 years ago
Read 2 more answers
Other questions:
  • I need help with this. Thanks
    15·1 answer
  • You sight a rock climber on a cliff at a 32 to the power of degree angle of elevation. Your eye level is 6 ft above the ground a
    12·1 answer
  • A new car is purchased for $17,000 the value of the car depreciates at 12.25% per year what will the value of the car be to the
    14·1 answer
  • I need help on math
    14·1 answer
  • Write an explicit formula for sequence<br> The Given Sequence is..<br> 3,-6,12,-24..
    15·1 answer
  • Jaden is participating in a 4-day cross -country biking challenge. He biked for 56, 60, and 47 miles on the first three days. Ov
    11·1 answer
  • PLEASE HELP QUICK I NEED IT TO PASS
    9·2 answers
  • A bakery sells 6350 muffins in 2010. The bakery sells 8310 muffins in 2015. Write a linear model that represents the number $y$
    14·1 answer
  • Write the equation of the given line in slope-intercept form:<br> (-1,2) and (1,-4)
    15·1 answer
  • BRAINLIEST FOR RIGHT ANSWER!!
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!