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3 years ago

6

Evaluate 1/x^-2 for x = 7. A. -49 B. 1/49 C. 49

2 answers:

Ganezh [65]3 years ago

6 0

The answer to this question is c

mestny [16]3 years ago

3 0

$\frac{a}{{b}^{n} } = a \times {b}^{ - n}$
Using this formula, it will become:
$1 \times {x}^{2}$
Which equals 1 x 7 x 7 which is 49...
Which means the answer is c..

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25 points? pls idk the answer :((( help D:

DedPeter [7]

Answer:

18x = 7.2

x =.4

Step-by-step explanation:

Let x = the weight of one box

We have 18 boxes that weigh 7.2 lbs

18x = 7.2

Divide each side by 18

18x/18 = 7.2/18

x =.4

6 0

3 years ago

Read 2 more answers

What are the exact solutions of x2 − 5x − 7 = 0, where x equals negative b plus or minus the square root of b squared minus 4 ti

Marat540 [252]

Answer:

$x = \frac{5 + \sqrt{53}}{2}$ or $x = \frac{5 - \sqrt{53}}{2}$

Step-by-step explanation:

Given

$x^2 - 5x - 7 = 0$

Required

Solve for x using:

$x = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}$

First, we need to identify a, b and c

The general form of a quadratic equation is:

$ax^2 + bx + c = 0$

So, by comparison with $x^2 - 5x - 7 = 0$

$a = 1$ $b = -5$ $c = -7$

Substitute these values of a, b and c in

$x = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}$

$x = \frac{-(-5) \± \sqrt{(-5)^2 - 4 * 1 * -7}}{2 * 1}$

$x = \frac{5 \± \sqrt{25 +28}}{2}$

$x = \frac{5 \± \sqrt{53}}{2}$

Split the expression to two

$x = \frac{5 + \sqrt{53}}{2}$ or $x = \frac{5 - \sqrt{53}}{2}$

To solve further in decimal form, we have

$x = \frac{5 + 7.28}{2}$ or $x = \frac{5 - 7.28}{2}$

$x = \frac{12.28}{2}$ or $x = \frac{-2.28}{2}$

$x = 6.14$ or $x = -1.14$

4 0

3 years ago

Please help with the question in the picture!

Stella [2.4K]

Answer:

Tan C = 3/4

Step-by-step explanation:

Given-

∠ A = 90°, sin C = 3 / 5

<u>METHOD - I</u>

<u><em>Sin² C + Cos² C = 1</em></u>

Cos² C = 1 - Sin² C

Cos² C = $1 - \frac{9}{25}$

Cos² C = $\frac{25 - 9}{25}$

Cos² C = $\frac{16}{25}$

Cos C = $\sqrt{\frac{16}{25} }$

Cos C = $\frac{4}{5}$

As we know that

Tan C = $\frac{Sin C}{Cos C }$

<em>Tan C = $\frac{\frac{3}{5} }{\frac{4}{5} }$ </em>

<em>Tan C = $\frac{3}{4}$ </em>

<u>METHOD - II</u>

Given Sin C = $\frac{3}{5} = \frac{Height}{Hypotenuse}$

therefore,

AB ( Height ) = 3; BC ( Hypotenuse) = 5

<em>∵ ΔABC is Right triangle.</em>

<em>∴ By Pythagorean Theorem-</em>

<em>AB² + AC² = BC²</em>

<em>AC² </em><em>= </em><em>BC² </em><em>- </em><em> AB</em><em>² </em>

<em>AC² = 5² - 3²</em>

<em>AC² = 25 - 9</em>

<em>AC² = 16</em>

<em>AC ( Base) = 4</em>

<em>Since, </em>

<em>Tan C = $\frac{Height}{Base}$ </em>

<em>Tan C = $\frac{AB}{AC}$ </em>

<em>Hence Tan C = $\frac{3}{4}$ </em>

<em />

4 0

3 years ago

5 less than three times a number is 10

velikii [3]

5•2=10
2 is less then 3

5 0

3 years ago

Read 2 more answers

Tanner collected 360 cans and cans and bottles while fundraising for his baseball team this was 40% of what Reggie collected how

Colt1911 [192]

360÷0.40 =144

360 +144 = 504

7 0

3 years ago