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3 years ago

Evaluate: 2^-2 x (13x3)-5^3

Mathematics

2 answers:

Lapatulllka [165]3 years ago

6 0

2^-2 x (13x3)-5^3

1/ (2^2) * 39 - 125

1/4 *39 -125

39/4 -125

9 3/4 - 125

factor out -1

- (125-9 3/4)

borrow to subtract the fraction

- (124 4/4 - 9 3/4)

- (115 1/4)

-115 1/4

Rainbow [258]3 years ago

3 0

Answer:

-115.25

2^-2 x (13x3)-5^3

2^-2 x (39)- 5^3

2^-2 x (39)- 125

0.25 x (39) - 125

9.75 - 125

-115.25

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Monica [59]

Answer:24

Step-by-step explanation:

5 0

3 years ago

A kite is stuck in a 36-ft tree. If the angle of elevation from the kite and the ground is 12, find the length of the kite.

yanalaym [24]

Answer:

173.15 ft.

Step-by-step explanation:

Please find the attachment.

Let L be the length of kite.

We have been given that a kite is stuck in 36-ft tree. The angle of elevation from the kite and the ground is 12.

We can see from our attachment that kite and tree form a right triangle. height of tree is opposite of angle of elevation and length of kite is hypotenuse.

Since we know that Sine relates the opposite and hypotenuse of a right triangle, so we will use sine to find the length of kite.

$sin(12)=\frac{36}{L}$

$L=\frac{36}{sin(12)}$

$L=\frac{36}{0.207911690818}$

$L=173.1504364105882792\approx 173.15$

Therefore, the length of kite is 173.15 ft.

4 0

3 years ago

A student is given that point P(a, b) lies on the terminal ray of angle Theta, which is between StartFraction 3 pi Over 2 EndFra

Harman [31]

Answer:

A.

The student made an error in step 3 because a is positive in Quadrant IV; therefore,

$cos\theta = \frac{a\sqrt{a^2 + b^2}}{a^2 + b^2}$

Step-by-step explanation:

Given

$P\ (a,b)$

$r = \± \sqrt{(a)^2 + (b)^2}$

$cos\theta = \frac{-a}{\sqrt{a^2 + b^2}} = -\frac{\sqrt{a^2 + b^2}}{a^2 + b^2}$

Required

Where and which error did the student make

Given that the angle is in the 4th quadrant;

The value of r is positive, a is positive but b is negative;

Hence;

$r = \sqrt{(a)^2 + (b)^2}$

Since a belongs to the x axis and b belongs to the y axis;

$cos\theta$ is calculated as thus

$cos\theta = \frac{a}{r}$

Substitute $r = \sqrt{(a)^2 + (b)^2}$

$cos\theta = \frac{a}{\sqrt{(a)^2 + (b)^2}}$

$cos\theta = \frac{a}{\sqrt{a^2 + b^2}}$

Rationalize the denominator

$cos\theta = \frac{a}{\sqrt{a^2 + b^2}} * \frac{\sqrt{a^2 + b^2}}{\sqrt{a^2 + b^2}}$

$cos\theta = \frac{a\sqrt{a^2 + b^2}}{a^2 + b^2}$

So, from the list of given options;

The student's mistake is that a is positive in quadrant iv and his error is in step 3

3 0

3 years ago

Need help please?!?!?! Extra points!!!

andrey2020 [161]

Answer:

4.19

Step-by-step explanation:

just use the formula 2pir^2

8 0

3 years ago

Bag contains 2 red marbles 2Green marbles and 4 blue marbles if we choose a marble than other marble without putting the first o

Murrr4er [49]

Answer:

The probability that the first marvel will be red and the second will be green is 7.14%.

Step-by-step explanation:

Since a bag contains 2 red marbles, 2 green marbles and 4 blue marbles, if we choose a marble and then other marble without putting the first one back in the bag, to determine what is the probability that the first marvel will be red and the second will be green, the following calculation must be performed:

2 + 2 + 4 = 8

2/8 x 2/7 = X

0.25 x 0.2857 = X

0.0714 = X

Therefore, the probability that the first marvel will be red and the second will be green is 7.14%.

6 0

2 years ago