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Arte-miy333 [17]
3 years ago
14

Solve this equation by completing the square: x2 + 4x – 13 = –8

Mathematics
1 answer:
marishachu [46]3 years ago
6 0

Answer:

x = 1 or x = -5

Step-by-step explanation:

We are given;

  • The quadratic equation, x² + 4x - 13 = -8

We are required to solve the equation using the completing square method.

To do this, we use the following steps;

Step 1: We make sure the coefficient of x² is one

x² + 4x - 13 = -8

Step 2: Combine the like terms (take the constant term to the other side)

x² + 4x - 13 = -8

x² + 4x = -8 + 13

we get

x² + 4x  = 5

Step 3: We add the square of half the coefficient of x on both sides of the equation

Coefficient of x = 4

Half of coefficient of x = 2

Square of half the coefficient of x = 2² (4)

We get;

x² + 4x + (2²)  = 5 + (2²)

Step 4: Put x and 2 under one square and the solve the other side of the equation.

We get

(x + 2)² = 5 + 4

(x + 2)² = 9

Step 5: Get the square root on both sides of the equation;

(x + 2)² = 9

√(x + 2)² = ±√9

(x + 2)= ±3

Therefore;

x+2 = + 3 or x + 2 = -3

Thus, x = 1 or -5

The solution of the equation is x = 1 or x = -5

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Together they sold 27 rolls of wrapping paper. 
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3 years ago
Question<br> Find the x- and y-intercepts of the parabola y<br> =<br> =-3x²<br> -<br> 10x 10.<br> -
algol13

Answer:

-100/3,0

Step-by-step explanation:

substitute in 0 for y and solve for x. To find the y-intercept, substitute in 0 for x and solve for y.

if that makes sense Hope this helps pls brainliest have a nice day :>

5 0
2 years ago
Read 2 more answers
Find the quotient and any excluded values.<br><br> (x + 5/x^2 + 9x + 20)/(x^2-16/x-4)
Wittaler [7]
By  <span>(x + 5/x^2 + 9x + 20) you apparently meant the following:

         x+5
 ----------------------
   x^2 + 9x + 20

and by 

</span><span>(x^2-16/x-4)
                                       x^2-16
you apparently meant ---------------
                                         x - 4

Please use additional parentheses for clarity.

Dividing,

</span>         x+5                   (x-4)(x+4)
 ----------------------  *  ---------------
   x^2 + 9x + 20                  x-4

Now, x^2 + 9x + 20 factors into   (x+4)(x+5), so what we have now is

       (x+5)(x+4)
------------------------- = 1           This is true for all x, so there are no exclusions.
    (x+4)(x+5)
3 0
3 years ago
This bottle holds 720ml.It is 3/8 full.How much liquid is in the bottle?
chubhunter [2.5K]

Answer: It should be 270 ml

Step-by-step explanation:

To find 3/8 of 720, we need to know 1/8

Divide 720 by 8, this gives you 90

Now multiply 90 by 3 to get 3/8

Answer is 270 ml

4 0
2 years ago
Help
pychu [463]
Use the following formula valid fo every polyhedron. 

v-e+f=2 
<span>
Search for Euler characteristic, or Euler-Poicare characteristic for more depth about this formula </span>

v= number of vertices 

e=number of edges 

f=number of faces 

<span>You get v=13

<span>I hope my answer has come to your help. Thank you for posting your question here in </span>Brainly<span>. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!</span>
</span>
3 0
3 years ago
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