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Delicious77 [7]
2 years ago
12

How do you rewrite an equation by completing the square? x^2+10x+21=0

Mathematics
1 answer:
AleksAgata [21]2 years ago
7 0

Answer:

Step-by-step explanation:

x²+10x+21=0

x²+10x+(10/2)²-(10/2)²+21=0

x²+10x+25-25+21=0

(x+5)²-4=0

(x+5)²=4

(x+y)²=(x+y)(x+y)=x(x+y)+y(x+y)=x²+xy+xy+y²=x²+2xy+y²

(x+y)²=x²+2xy+y²

coefficient of x=2y

y²=[(coefficient of x)/2]²=(2y/2)²=y²

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Find the area. The figure is not drawn to scale. Please show work
Irina-Kira [14]

Answer:

13.8 square feet

Step-by-step explanation:

To find the area of a triangle you use the formula a = 1/2 bh

a = 1/2 (6.9) (4) = 13.8

(simplier to understand) a = 1/2 (6.9) (4) = 27.6 divided by 1/2 = 13.8

6 0
3 years ago
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What is the range of the function?
levacccp [35]

Answer:

e equels MC squared

Step-by-step explanation:

7 0
3 years ago
A. 25,600π in3<br><br><br><br> B. 10,240π in3<br><br><br><br> C. 1280π in3<br><br><br> D. 640π in3
NeX [460]

Answer: The correct answer is B; 10,240π in³

Step-by-step explanation: To calculate the volume of a cylinder, the given formular is

Volume = π r² h, where

radius (r) = 16

height (h) = 40

Pi (π) = 3.14

It is important to take note that in questions like these, the value of pi is usually given as 3.14 or 22/7. However, for this particular question, the answer should be expressed in terms of pi, (that is, the answer must include pi). For that reason we shall leave pi as it is, and we shall not use it's value when applying the formular.

Therefore, inserting the values of radius, height and pi into our formular, we now have;

Volume = π r² h

Volume = π x 16² x 40

Volume = π x 256 x 40

Volume = π x 10,240

Therefore the exact volume of the cylinder = 10,240π in³

5 0
3 years ago
Determine the next step for solving the quadratic equation by completing the square
GaryK [48]

Answer:

  • The two solutions are:           x=\frac{1}{2}+/-\frac{\sqrt{7} }{2}

  • The next and every step are below.

Explanation:

1. -3=-2x^2+2x    : Given (addition property / add - 3 to both sides)

2. -3 = - 2(x^2-x)    : Given (commom factor - 2)

3. -3-1/2=-2(x^2-x+1/4)

    To obtain the perfect square it was added the square of half of the coefficient of x: (1/2)² = 1/4, inside the parenthesis.

Since, the terms inside the parentthesis are multiplied by - 2, you have to add - 2 (1/4) = - 1/2 to the left side of the equation.

4. Now, you have that the trinomial x² - x + 1/4 is a square perfect trinomial which is factored as (x - 1/2)² and get the expression:

-7/2=-2(x-1/2)^2

5. Divide both sides by - 2 to get the next expression:

-7/4=(x-1/2)^2

6. The last step is to extract squere root from both sides of the equality:

(x-1/2)=+/-\sqrt{\frac{7}{4}}\\ \\ x-1/2=+/-\frac{\sqrt{7} }{2}\\ \\ x=\frac{1}{2}+/-\frac{\sqrt{7} }{2}

8 0
2 years ago
Need help nadding and subtracting functions
SCORPION-xisa [38]

Answer:

2x² + \frac{3}{2} x - 5

Step-by-step explanation:

(f + g)(x) = f(x) + g(x), thus

f(x) + g(x)

= \frac{x}{2} - 2 + 2x² + x - 3 ← collect like terms

= 2x² + \frac{3}{2} x - 5

3 0
2 years ago
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