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
devlian [24]
3 years ago
14

Which equations are correct

Mathematics
1 answer:
VARVARA [1.3K]3 years ago
3 0

Answer:

2nd, 3rd and 4th equations are correct.

Step-by-step explanation:

-4x^2(2x^2+5)=-8x^4-20x^2\\\\

is right because each term inside is multiplied by -4x square and we find the answer is right.

-4b^3(5b^2+3)\\\\\\= -4(5)(b^3)(b^2) =-20b^6-12b^3\\

Hence correctly done.

-5a^4(2a^2+4)=  (-5)(2)(a^4)(a^2)+(-5)(4)(a^4\\-10a^6-20a^4\\

Correctly done.

-6^4(4y^2+2)=-24y^8-12y^4\\= -(6)(6)(6)(6) 4y^2 -(6)(6)(6)(6) (2)

should be the right answer.

But instead only 6 is multiplied by inner terms. Hence wrong.

I answer is wrong and others are right.

You might be interested in
What is the vertex of the graph of the function f(x) = x2 − 4x?
Vsevolod [243]

Answer:

(2, -4).

Step-by-step explanation:

x^2 - 4x

= (x - 2)^2 - 4.

So the vertex is at

(2, -4).

6 0
3 years ago
Read 2 more answers
Priscilla has 4.3*10^8 strands of hair on her head. Diego has 8.7*10^5 strands of hair on his head. How many more strands of hai
MrMuchimi
<h3>Answer:  4.2913 * 10^8</h3>

====================================================

Work Shown:

4.3*10^8 = 4.3 * 10^(3+5)

4.3*10^8 = 4.3 * 10^3*10^5

4.3*10^8 = 4.3*1000*10^5

4.3*10^8 = 4300*10^5

Priscilla has 4300*10^5 strands of hair while Diego has 8.7 * 10^5 strands. Subtract the values out front: 4300-8.7 = 4291.3

Then tack on the "*10^5" portion to get 4291.3*10^5

The difference in the number of strands is 4291.3*10^5

Convert this to scientific notation to get the final answer.

4291.3*10^5 = (4291.3)*10^5

4291.3*10^5 = (4.2913 * 1000)*10^5

4291.3*10^5 = 4.2913 * 1000*10^5

4291.3*10^5 = 4.2913 * 10^3*10^5

4291.3*10^5 = 4.2913 * 10^(3+5)

4291.3*10^5 = 4.2913 * 10^8

Note: The number 4.2913 * 10^8 expands out to 429,130,000 which is a little over 429 million.

6 0
3 years ago
Felix is now six times as old as Debbie. In twelve years time Felix will be two times as old as Debbie. How old are they​
Minchanka [31]

Step-by-step explanation:

let debbie be x years

let felix be 6x years

in 12 years felix will be 2x older than debbie

do the calc

6 0
3 years ago
The price of a watch was increased by 20% to £144. What was the price before the increase
MAXImum [283]

Answer:

120 pounds

Step-by-step explanation:

Since the new cost is 144 pounds and this is 20% more,  this is 120% of the original price. Remember 100+20 = 120. To find the original price set up a proportion with these values:

Solve for the original price by cross multiplying numerator with denominator.

x(120) = 144(100)

120x = 14400

x= 120 pounds

3 0
3 years ago
Avani wrote the linear equation y = 5 x + 4. Then, she wrote the equation of the line that is perpendicular to y = 5 x + 4 and t
Margarita [4]

Avani wrote the linear equation y = 5x + 4. Then, she wrote the equation of the line that is perpendicular to y = 5x+ 4 and that passes through (15,–2). If her new equation is in the form  y-\frac{1}{5}x+b, what is the value of b?

\bf y=mx+b

  • m is the slope
  • b is the y-intercept

The equation of a line that is perpendicular to another line always has the opposite reciprocal slope. In the original equation, the slope is 5. The opposite of 5, which refers to the sign, is -5. The reciprocal of -5 is -1/5. That means the slope of the new line is -1/5.

The perpendicular line:

  • Has a slope of -\frac{1}{5}
  • Passes through the point (15, -2)

To find the equation of a line that passes through a specific point, you need to use slope-intercept form.

\bf y-y_{1} =m(x-x_{1})

  • y₁ is the y-value of the point
  • m is the slope
  • x₁ is the x-value of the point

y₁ is -2, m is -1/5,  and x₁ is 15.

Substitute the known values into the equation:

y-(-2)=-\frac{1}{5}(x-15) \rightarrow y+2= -\frac{1}{5}(x-15)

Open the parentheses and distribute:

-\frac{1}{5}(x-15) \rightarrow -\frac{1}{5} \cdot x\ +  -\frac{1}{5} \cdot -15 \rightarrow -\frac{1}{5}x +3

The new equation will be:

y+2=-\frac{1}{5}x+3

Lastly, you need to move the positive 2 to the other side to keep it in y = mx + b form.

y+2-2=-\frac{1}{5}x+3-2 \rightarrow y=-\frac{1}{5}x+1

The equation of the perpendicular line is:

\bf y=-\frac{1}{5}x+1

The value of b is 1.

5 0
3 years ago
Other questions:
  • 72 348 675 125 what is the value of the 2 in 72
    13·1 answer
  • Simplify.<br> X+1<br> - 1 - 4.2
    14·2 answers
  • 10. Write the equation of the line that is parallel tox-3y = 9 and passes through the point (3,-1).​
    9·1 answer
  • 10.6 - 3x when x is equal to 4.5.​
    7·2 answers
  • (3,2), (3,5)
    15·1 answer
  • Ratio Question;
    14·1 answer
  • Y = 3/5x + 5<br><br><br> y = -3/5x + 5<br><br><br> y = 3/5x - 5<br><br><br> y = -3/5x - 5
    9·2 answers
  • What is the decimal equivalent of 8/3?<br> A. 2.6<br> B. 0.375<br> C. 8.3<br> D. 26
    7·2 answers
  • How do i solve this?
    5·1 answer
  • A photograph with a width of 3 inches and a length of 5 inches will be enlarged so that the length is 40 inches. What will the w
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!