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2 years ago

Express x2+ 4x - 7 in the form (x + a) - b where a and b are integers. please help 100 points

Mathematics

1 answer:

Darya [45]2 years ago

4 0

Answer:

(x + 2)^2 - 11.

Step-by-step explanation:

f(x) = x^2 + 4x - 7

Now x^2 + 4x = (x + 2)^2 - 4 so we have:

f(x) = (x + 2)^2 - 4 - 7

f(x) = (x + 2)^2 - 11.

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I WANT SOLUTION AND EXPLANATION ANSWER IS GIVEN AT LAST!!!

kozerog [31]

<h3><u>Question</u><u>:</u></h3>

<u>The difference between a 2-digit number and the number formed by reversing its digits is 45. If the sum of the digits of the original number is 13, then find the number. </u>

<h3><u>Statement</u><u>:</u></h3>

<u>The difference between a 2-digit number and the number formed by reversing its digits is 45. </u><u>T</u><u>he sum of the digits of the original number is 13</u><u>.</u>

<h3><u>Solution:</u></h3>

Let one of the digit of the original number be x.
So, the other digit = (13-x)
Therefore, the two digit number = 10(13-x) + x = 130-10x+x = 130-9x
The number obtained after interchanging the digits is 10x+(13-x) =9x+13
Therefore, by the problem

130-9x-(9x+13) = 45

or, 130-9x- 9x-13 = 45

or, -18x = 45-130+13

or, -18x= -72

or, x = 72/18 = 4

or, x = 4

So, the original number = 130-9x = 130 -9(4) = 130 - 36 = 94

<h3>Answer:</h3>

The number is 94.

I think the answer you have given isn't right. The answer should be 94.

7 0

2 years ago

Which is less, 8 ½ pounds or 130 ounces?

Harman [31]

Do you know how to convert pounds to ounces

3 0

2 years ago

In a recent survey, 10 percent of the participants rated Pepsi as being "concerned with my health." PepsiCo's response included

hichkok12 [17]

Answer:

The statistic for this case would be given by:

$z=\frac{0.18 -0.1}{\sqrt{\frac{0.1(1-0.1)}{100}}}=2.67$

Step-by-step explanation:

Infromation provided

n=100 represent the random sample selected

X=18 represent the people who rates Pepsi as being "concerned with my health"

$\hat p=\frac{18}{100}=0.18$ estimated proportion of people who rates Pepsi as being "concerned with my health"

$p_o=0.1$ is the value that reference to compare

z would represent the statistic

Hypothesis to test

For this case we can assume that the interest is check if the proportion of people who rates Pepsi as being "concerned with my health" is equal to 0.1 or not , then the system of hypothesis are:

Null hypothesis: $p=0.1$

Alternative hypothesis: $p \neq 0.1$

The satistic for this one sample proportion test is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

Replacing the info given we got:

$z=\frac{0.18 -0.1}{\sqrt{\frac{0.1(1-0.1)}{100}}}=2.67$

7 0

2 years ago

Parallelogram (x 40) and (3x)

fenix001 [56]

8 0

3 years ago

PLEASE help! Math help? :)

stepan [7]

Answer: 39.2

Check out the attached image

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

Explanation:

Draw out the triangle or use the diagram provided by your teacher. It should look something similar to what I've attached.

Let m = length of side XZ

We are given that
angle Y = 75 degrees
angle Z = 67 degrees
which are the green angles shown in the diagram

Use the fact that the three angles (X,Y,Z) add to 180 degrees to find angle X
X+Y+Z = 180
X+75+67 = 180
X+142 = 180
X+142-142 = 180-142
X = 38

Now use the law of sines to find m
sin(X)/YZ = sin(Y)/XZ
sin(38)/25 = sin(75)/m
m*sin(38) = 25*sin(75)
m = 25*sin(75)/sin(38)
m = 39.22309 <<<--- make sure your calculator is in degree mode
m = 39.2

So XZ is roughly 39.2 feet in length

4 0

2 years ago