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
VashaNatasha [74]
3 years ago
12

Two students solved the same multi-step equation. Which student is correct? Explain the error. Student A Student B 2x - 4(3x + 6

) = -6(2x + 1) - 4 2x - 4(3x + 6) = -6(2x + 1) - 4 2x - 12x + 6 = -12x + 1 - 4 2x - 12x - 24 = -12x - 6 - 4 -10x + 6 = -12x - 3 -10x - 24 = -12x - 10 2x = -9 2x = 14 x = -4 _1 2 x = 7
Mathematics
1 answer:
Gnom [1K]3 years ago
8 0

Answer:

Student B is correct

Student A failed to distribute -4 and -6 when opening the brackets in the first step

Step-by-step explanation:

The solution Student A gave was:

2x - 4(3x + 6) = -6(2x + 1) - 4

2x - 12x + 6 = -12x + 1 - 4

-10x + 6 = -12x - 3

2x = -9

x = -4 _1 2 ( -4 1/2)

The solution Student B gave was:

2x - 4(3x + 6) = -6(2x + 1) - 4

2x - 12x - 24 = -12x - 6 - 4

-10x - 24 = -12x - 10

2x = 14

x = 7

Student B is correct.

Explanation of the error:

Student A failed to distribute -4 and -6 when opening the brackets in the first step.

That is,

2x - 4(3x + 6) = -6(2x + 1) - 4

To open this bracket, we will distribute, -4 and -6 so that we get

2x (-4 × 3x) + (-4 × +6) = (-6×2x) + (-6 × +1) - 4

Then we will get

2x -12x -24 = -12x -6 -4

Adding the like terms

-10x - 24 = -12x - 10

Collecting like terms

-10x + 12x = -10 + 24

∴ 2x = 14

x = 14 / 2

Hence,

x = 7

You might be interested in
The table slow shows Larry's scores on 6 different math tests. What is Larry's mean score on the 6 tests?
VladimirAG [237]

Answer:

86

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
A recent study asked U. S. Adults to name 10 historic events that occurred during their lifetime that have had the greatest impa
Nadusha1986 [10]

Using the z-distribution, as we are working with a proportion, it is found that the 99% confidence interval for the proportion of all U. S. Adults who would include the 9/11 attacks on their list of 10 historic events is (0.7458, 0.7942). It means that we are 99% sure that the true proportion for all U.S. adults is between these two bounds.

<h3>What is a confidence interval of proportions?</h3>

A confidence interval of proportions is given by:

\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}

In which:

  • \pi is the sample proportion.
  • z is the critical value.
  • n is the sample size.

In this problem, the parameters are:

z = 2.575, n = 2000, \pi = 0.77

The lower limit of this interval is:

\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.77 - 2.575\sqrt{\frac{0.77(0.23)}{2000}} = 0.7458

The upper limit of this interval is:

\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.77 + 2.575\sqrt{\frac{0.77(0.23)}{2000}} = 0.7942

The 99% confidence interval for the proportion of all U. S. Adults who would include the 9/11 attacks on their list of 10 historic events is (0.7458, 0.7942). It means that we are 99% sure that the true proportion for all U.S. adults is between these two bounds.

More can be learned about the z-distribution at brainly.com/question/25890103

7 0
3 years ago
Which equation could be used to find the height of the flagpole
Sauron [17]
X = height of pole (in meters)

With respect to the 50 degree angle, the side x is the opposite leg. It is the leg furthest from the reference angle. The hypotenuse is 5 meters. 

The trig function sine ties together the opposite and hypotenuse

sin(angle) = opposite/hypotenuse
sin(50) = x/5
5*sin(50) = x .... multiply both sides by 5
x = 5*sin(50)

------------------

Since x = 5*sin(50) isn't listed as an answer choice, let's try using cosine. We can't use it right away because we don't know the adjacent side. What we can do is change the reference angle. The missing angle of the triangle is 90-50 = 40 degrees. Let's make the 40 degree angle the reference angle

So x is now the adjacent side with respect to the 40 degree reference angle. The hypotenuse is always the longest side. The hypotenuse stays at 5.

cos(angle) = adjacent/hypotenuse
cos(40) = x/5
5*cos(40) = x
x = 5*cos(40)

This expression is listed. The answer is choice B

4 0
3 years ago
The product od 2 and y is at least 10
alexgriva [62]
Hello There!

It could be represented by this:
xy \geq 10

Hope This Helps You!
Good Luck :) 

- Hannah ❤
8 0
4 years ago
What 9 intergers are between -3.5 and 5.5
laila [671]
3.5  3.4   3.3   3.2   3.1   3   -5.5  -1  -2 
6 0
3 years ago
Other questions:
  • To obtain the length of an arc, what fraction is multiplied by the circumference of a circle (C = 2πr)?
    7·2 answers
  • Vanessa ate 1/3 of a pizza for dinner. Her brother Van ate 1/2 of the leftover pizza. How much of the pizza did Van eat?
    12·1 answer
  • Part 1.] Does the graph have even symmetry, odd symmetry, or neither?
    5·1 answer
  • A bag contains 5 red, 5 blue, 4 green, and 2 yellow marbles. Find the probability of randomly choosing: a green then yellow (ind
    9·2 answers
  • Solve the equation for x <br> 3/10x-1/5=1
    7·1 answer
  • If a ferry boat covers 28 miles in 4 hours how much distance will it cover in 12 hours?
    13·2 answers
  • 5 dollars less on dinner than James spent
    11·2 answers
  • Helllpppp): please !!
    11·2 answers
  • _________% of 50 shirts is 35 shirts what is it
    14·1 answer
  • Find the zeros from the factored form Quadratic Equation y=-x(x-3) ( ,0) &amp; ( ,0)​
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!