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3 years ago

Rewrite the equation by completing the square. x^2 + 2x – 48 = 0

Mathematics

1 answer:

slamgirl [31]3 years ago

3 0

Answer:

(x+1)^2 = 49

x = 6 x = -8

Step-by-step explanation:

x^2 + 2x – 48 = 0

Add 48 to each side

x^2 + 2x =48

Take the coefficient of x

Divide by 2

2/2=1

Square it

1^2 =1

x^2 + 2x +1=48+1

x^2 +2x+1 = 49

(x+1)^2 = 49

Take the square root of each side

sqrt((x+1)^2) =±sqrt( 49)

x+1 = ±7

Subtract 1 from each side

x+1-1 = -1 ±7

x = -1+7 x = -1 -7

x = 6 x = -8

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How the heck do I do this? And what’s the answer?

stira [4]

Answer:

Option A

Step-by-step explanation:

We need to find two expressions that, when simplified, give the same results.

1) First, simplify the expression stated in the question. Multiply each of the terms in the parentheses by the number that is next to them. This would mean you have to multiply both 9x and -6 by $\frac{2}{3}$ . You also have to multiply $\frac{1}{2}x$ and $-\frac{1}{2}$ by 4. Then, simplify.

$\frac{2}{3}(9x-6) + 4 (\frac{1}{2} x - \frac{1}{2})\\\frac{18}{3}x- \frac{12}{3} + \frac{4}{2}x -\frac{4}{2} \\6x - 4 + 2x - 2$

2) Now, combine the like terms.

$6x - 4 + 2x - 2$

$8x - 6$

So, we need to find which of the expressions listed equal 8x - 6.

3) Let's try option A. Do the same as before. Multiply each of the terms in the parentheses by the number that is next to them. So, multiply 4x and -12 by $\frac{3}{4}$ . Also, multiply 30x and 18 by $\frac{1}{6}$ . Then, combine like terms and simplify.

$\frac{3}{4} (4x-12) + \frac{1}{6}(30x + 18)\\\frac{12}{4}x-\frac{36}{4} + \frac{30}{6} x + \frac{18}{6} \\3x - 9 + 5x + 3 \\8x - 6$

This also equals 8x - 6. Therefore, option A is the answer.

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2 years ago

Evaluate each expression<br><br> 5.12x - 7

galina1969 [7]

Answer:

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........

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2 years ago

Solve the absolute value equation<br> algebraically: 3|2x - 3| + 2 = 3

kupik [55]

Answer:

$3 |2x - 3| = 1$

$3 |2x - 3| = 1 \\ 6x - 9 = 1 \\ 6x = 10 \\ x = \frac{10}{6} = \frac{5}{3}$

$3 |2x - 3| = - 1 \\ 6x - 9 = - 1 \\ 6x = 8 \\ x = \frac{4}{3}$

$x = \frac{5}{3} x = \frac{4}{3}$

I am sorry but I am not sure of this :(

7 0

2 years ago

benito read 14 books in 3 months, which was 35% of the number of books he had signed up to read during the school year .how many

lianna [129]

14 books in 3 months is 35%
all of books is 100%

14- 35%
x- 100%
we calculate from proportions, crosswise:
$x=\frac{14*100}{35}=\frac{1400}{35}=40$

Answer: Benito sign up to read 40 books.

Greetings,
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3 years ago

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faust18 [17]

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2 years ago

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