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marissa [1.9K]
3 years ago
5

How do you break down this question18 + 22 = 21 +

Mathematics
1 answer:
Gala2k [10]3 years ago
5 0
18 plus 22 is 40 so it is equivalent to 21 plus 19
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Complete the square to write the quadratic expression in vertex form.
Anvisha [2.4K]

Answer:

1. (x - 3)² = 8

2. (x + 2)² = 3

3. (x + 6)² = $ \frac{101}{2} $

4. (x + 3)² = 27

5. (x + 4)² = 13

6.  $ \bigg( x - \frac{15}{9} \bigg) ^2 = \frac{261}{81} = \frac{29}{9} $

Step-by-step explanation:

Completion of Square: $ (x - a) ^2 = x^2 - 2ax + a^2 $

In the following problems the terms in the RHS of the above equation may be missing. We balance the equation. Simplify it and re write it in terms of LHS.

1. x² - 6x + 1 = 0

Taking the constant term to the other side, we get:

x² - 6x = - 1

⇒ x² - 2(3)x = -1

⇒ x² -2(3)x + 9 = - 1 + 9  [Adding 9 to both the sides]

⇒ x² -2(3)x + 3² = 8

⇒ (x - 3)² = 8 is the answer.

2. 3x² + 12x + 3 = 0

Note that the co-effecient of x² is not 1. We make it 1, by dividing the whole equation by 3. And then proceed like the previous problem.

3x² + 12x = -3

Dividing by 3 through out, x² + 4x = - 1

⇒ x² + 2(2) + 4 = -1 + 4

⇒ x² +2(2) + 2² = 3

⇒ (x + 2)² = 3 is the answer.

3. 2x² + 24x = 29

x² + 12x = $ \frac{29}{2} $

⇒ x² + 2(6)x + 36 = $ \frac{29}{2} $ + 36

⇒ x² + 2(6)x + 6² = $ \frac{29 + 72}{2} $

⇒ (x + 6)² = $ \frac{101}{2} $ is the answer.

4. x² + 6x - 18 = 0

x² + 6x = 18

⇒ x² + 2(3)x = 18

⇒ x² + 2(3)x + 9 = 18 + 9

⇒ x² + 2(3)x + 3² = 27

⇒ (x + 3)² = 27 is the answer.

5. x² + 8x + 3 = 0

x² + 8x = -3

⇒ x² + 2(4)x = -3

⇒ x² + 2(4)x + 16 = - 3 + 16

⇒ x² + 2(4)x + 16 = 13

⇒ (x + 4)² = 13 is the answer.

6. 9x² - 30x + 6 = 0

9x² - 30x = - 6

⇒ x² $ - \frac{30}{9} $ x = - 6

$ \implies x^2 -2 \bigg( \frac{15}{9} \bigg )x + \frac{225}{81} = - 6 + \frac{225}{81} $

$ \implies x^2 - 2\bigg( \frac{15}{9} \bigg ) x + \bigg ( \frac{15}{9} \bigg ) ^2 = \frac{261}{81} $

$ \bigg( x - \frac{15}{9} \bigg) ^2 = \frac{261}{81} = \frac{29}{9} $ is the answer.

6 0
4 years ago
Approximate the zeros of the function. Round to the nearest tenth if necessary. f(x) = 4x^2 + 4x - 35. Explain each step on how
svet-max [94.6K]
4x²+4x-35=0
factor: (2x+7)(2x-5)=0
2x+7=0, or 2x-5=0
2x=-7 or 2x=5
x=-3.5 or x=2.5

I don't see any rounding necessary in this case. 

when you factor ax²+bx+c, you take the two factors of a and the two factors of c, one factor of a times one factor of c, the other factor of a times the other factors, the sum of the two products make b.
in this case, the factors of 4 is 2 and 2, the factors of -35 is -5 and 7. I line them up in the following way:
2    -5

2      7
then I multiple them diagonally, the top left 2 multiplying the bottom right 7=14, and the other 2 multiplying -5=-10, 14 and -10 make a sum of 4.

if you don't get the desired sum, switch the factors up and down till you have the right combination. Note: Do not switch left and right. 

I hope this makes sense to you.
8 0
3 years ago
Simplify the expression<br> –2 + 7(x + 8)
anastassius [24]

Answer:

54+7x

Step-by-step explanation:

-2+7(x+8)

-2+7x+56

54+7x

7 0
3 years ago
Read 2 more answers
Which of the following bottles contains the largest volume of shampoo?
yarga [219]

Answer:

B

Step-by-step explanation:

Converting all of them to Liters would be:

A 0.828065 L

B 2 L

C 0.016 L

D 0.9475 L

B is the largest.

7 0
3 years ago
The number y of hits a new website receives each month can be modeled by y = 4020ekt, where t represents the number of months th
Tcecarenko [31]
The answer would be 1.34
5 0
3 years ago
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