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3 years ago

13

2/x^2 in indices form explanation. I know the answer is 2x^-2 but I want an explanation.

1 answer:

Misha Larkins [42]3 years ago

7 0

Answer:

see explanation

Step-by-step explanation:

Using the rule of exponents

$\frac{1}{a^{m} }$ ⇔ $a^{-m}$ , then

$\frac{2}{x^2}$ = 2 × $\frac{1}{x^2}$ = 2 $x^{-2}$

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Which equation can be used to determine the distance between the origin and (–2, –4)?

Andreyy89

-2+(-4) i think :)))

3 0

3 years ago

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Tower one, a cube with a hexagonal prism measures 15.6cm. Tower two, a cube with a cylinder measures 18.3cm. Tower 3, a hexagona

lina2011 [118]

Answer:

$Tower 4 = 23.9cm$

Step-by-step explanation:

Given

Tower one = 15.6 cm

Tower two = 18.3 cm

Tower 3 = 13.9 cm.

Required:

Height of the 4th tower

Represent a cube by X; a cylinder by Y and a hexagonal prism by Z

Tower one, a cube with a hexagonal prism = X + Z = 15.6

Tower two, a cube with a cylinder = X + Y = 18.3

Tower 3, a hexagonal prism with a cylinder = Z + Y = 13.9

$X + Z = 15.6$ ----- Equation 1

$X + Y = 18.3$ ----- Equation 2

$Z + Y = 13.9$ ----- Equation 3

Subtract equation 1 from 2

$(X + Y = 18.3) - (X + Z = 15.6)$

$X - X + Y - Z = 18.3 -15.6$

$Y - Z = 18.3 -15.6$

$Y - Z = 2.7$ ---- Equation 4

Add Equation 4 to Equation 3

$(Y - Z = 2.7) + (Z + Y = 13.9)$

$Y + Y - Z + Z = 2.7+ 13.9$

$2Y = 2.7+ 13.9$

$2Y = 16.6$

Divide both sides by 2

$\frac{2Y}{2} = \frac{16.6}{2}$

$Y = \frac{16.6}{2}$

$Y = 8.3cm$

Substitute $Y = 8.3cm$ in Equation 2 and 3

$X + Y = 18.3$ ----- Equation 2

$X + 8.3 = 18.3$

Subtract 8.3 from both sides

$X + 8.3 - 8.3 = 18.3 - 8.3$

$X = 18.3 - 8.3$

$X = 10cm$

$Z + Y = 13.9$ ----- Equation 3

$Z + 8.3 = 13.9$

Subtract 8.3 from both sides

$Z + 8.3 - 8.3 = 13.9 - 8.3$

$Z = 13.9 - 8.3$

$Z = 5.6cm$

So, we have that

$X = 10cm$

$Y = 8.3cm$

$Z = 5.6cm$

The question states that the 4th tower is made up of the three shapes;

This implies that;

$Tower 4 = X + Y + Z$

$Tower 4 = 10cm + 8.3cm + 5.6cm$

$Tower 4 = 23.9cm$

The height of the 4th tower is 23.9cm

8 0

3 years ago

In a shipment of 56 vials, only 13 do not have hairline cracks. If you randomly select 3 vials from the shipment, in how many wa

Elden [556K]

Answer: 27434

Step-by-step explanation:

Given : Total number of vials = 56

Number of vials that do not have hairline cracks = 13

Then, Number of vials that have hairline cracks =56-13=43

Since , order of selection is not mattering here , so we combinations to find the number of ways.

The number of combinations of m thing r things at a time is given by :-

$^nC_r=\dfrac{n!}{r!(n-r)!}$

Now, the number of ways to select at least one out of 3 vials have a hairline crack will be :-

$^{13}C_2\cdot ^{43}C_{1}+^{13}C_{1}\cdot ^{43}C_{2}+^{13}C_0\cdot ^{43}C_{3}\\\\=\dfrac{13!}{2!(13-2)!}\cdot\dfrac{43!}{1!(42)!}+\dfrac{13!}{1!(12)!}\cdot\dfrac{43!}{2!(41)!}+\dfrac{13!}{0!(13)!}\cdot\dfrac{43!}{3!(40)!}\\\\=\dfrac{13\times12\times11!}{2\times11!}\cdot (43)+(13)\cdot\dfrac{43\times42\times41!}{2\times41!}+(1)\dfrac{43\times42\times41\times40!}{6\times40!}\\\\=3354+11739+12341=27434$

Hence, the required number of ways =27434

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3 years ago

The point (2,-5) is on the graph of which equation?

elena55 [62]

The answer is A,
if you plug in the points of (2,-5) into
y=x-7
-5=2-7
-5=-5
so the equation is true

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3 years ago

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PLEASE ANDWER<br> y = 10 x + 2<br> What is x?<br> Is this proportional?

IRISSAK [1]

Answer:

x the (x) value of the ordered pair, it is proportional.

Step-by-step explanation:

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3 years ago