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2 years ago

A girl's age in 12 years' time is the square of her present age. Find her present age.

Mathematics

2 answers:

SIZIF [17.4K]2 years ago

4 0

Answer:

Step-by-step explanation:

Let x represent her present age. The given relation is ...

x +12 = x^2

Putting this in standard form, we can factor it:

x^2 -x -12 = 0

(x -4)(x +3) = 0

Solutions to this quadratic are x = 4, x = -3. The -3 solution is extraneous in this context.

The girl's present age is 4.

harkovskaia [24]2 years ago

3 0

Answer: her present age is 4

Step-by-step explanation:

Proof: 4+12=16

Square root 4 is 16

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Find the domain of the function f(x)=<img src="https://tex.z-dn.net/?f=%5Csqrt%7Bx%5E3-16x%7D" id="TexFormula1" title="\sqrt{x^3

Anon25 [30]

Answer:

Please check the explanation.

Step-by-step explanation:

Given the function

$f\left(x\right)=\sqrt{x^3-16x}$

We know that the domain of the function is the set of input or arguments for which the function is real and defined.

In other words,

Domain refers to all the possible sets of input values on the x-axis.

Now, determine non-negative values for radicals so that we can sort out the domain values for which the function can be defined.

$x^3-16x\ge 0$

as x³ - 16x ≥ 0

$\left(x+4\right)\left(x-4\right)\ge \:0$

Thus, identifying the intervals:

$-4\le \:x\le \:0\quad \mathrm{or}\quad \:x\ge \:4$

Thus,

The domain of the function f(x) is:

$x\left(x+4\right)\left(x-4\right)\ge \:0\quad :\quad \begin{bmatrix}\mathrm{Solution:}\:&\:-4\le \:x\le \:0\quad \mathrm{or}\quad \:x\ge \:4\:\\ \:\mathrm{Interval\:Notation:}&\:\left[-4,\:0\right]\cup \:[4,\:\infty \:)\end{bmatrix}$

And the Least Value of the domain is -4.

3 0

3 years ago

And 18 ounce box of raisins cause $2.88 a 24 ounce box of raisins cost $3.60 which one is the better deal

nadya68 [22]

Answer:

the 24-ounce box

Step-by-step explanation:

18/2.88 = 6.25$

24/3.6 = 6.67$

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2 years ago

How can I use math to explain why other people's work is right or wrong?

valentinak56 [21]

Answer:

you can use math to explain others wrong by maybe doing calculations

Step-by-step explanation:

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3 years ago

While walking between gates at an airport, you notice a child running along a moving walkway. Estimating that the child runs at

tekilochka [14]

The speed of the moving walkway relative to the airport terminal exists at 1.84 m/s.

<h3>How to estimate the speed of the moving walkway relative to the airport terminal?</h3>

Let x be the speed of the walkway.

(2.8 + x) = speed of child moving in direction of the walkway

(2.8 - x) = speed of child moving against the direction of the walkway

Travel time = distance/speed

Travel time of child moving in direction of walkway = 23/(2.8+x)

Total elapsed time given = 29s

23/(2.8 + x)+ 23 / (2.8-x) = 29

LCD = (2.8 + x)(2.8 - x)

$23(2.8 - x) + 23(2.8 + x) = 29(2.8 + x)(2.8 -x)$

simplifying the equation, we get

$23*2.8-23x+23*2.8+23x=29(2.8^2-x^2)$

$23(2.8+2.8)/29=2.8^2-x^2$

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The speed of the moving walkway relative to the airport terminal exists at 1.84 m/s.

To learn more about Speed refer to:

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2 years ago

Change each of the following decimals to a fraction. Reduce your answer to its lowest terms.

cluponka [151]

7/100

3/10

21/125

3/ 2500

7/50

I simplified them for you

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3 years ago