Help me. quick,please. 20 points!!

If y=12, what is the value of 85y+8-80y?

finlep [7]

Answer: 68

Step-by-step explanation: Because I am smart

3 0

1 year ago

What is the image of point (4, 5) after a counterclockwise rotation of 270º about the origin?

andriy [413]

A <span>counterclockwise rotation of 270º about the origin is equivalent to a </span><span>clockwise rotation of 90º about the origin.

Given a point (4, 5), the x-value, i.e. 4 and the y-value, i.e. 5 are positive, hence the point is in the 1st quadrant of the xy-plane.

A clockwise rotation of </span><span>90º about the origin of a point in the first quadrant of the xy-plane will have its image in the fourth quadrant of the xy-plane. Thus the x-value of the image remains positive but the y-value of the image changes to negative.
Also the x-value and the y-value of the original figure is interchanged.
For example, given a point (a, b) in the first quadrant of the xy-plane, </span><span>a counterclockwise rotation of 270º about the origin which is equivalent to a <span>clockwise rotation of 90º about the origin will result in an image with the coordinate of (b, -a)</span>

Therefore, a </span><span>counterclockwise rotation of 270º about the origin </span><span>of the point (4, 5) will result in an image with the coordinate of (5, -4)</span> (option C)

3 0

3 years ago

What is the approximate volume of the cylinder? Use 3.14 for π.<br> 9 Hight and 4 length.

krek1111 [17]

Answer:

113.04

Step-by-step explanation:

Radius(r)= 4/2 = 2

Volume = r² x π x h

⇒ 4 x 3.14 x 9 = 113.04 (when using pi = 3.14)

hope this helps!

5 0

3 years ago

2. Find the general relation of the equation cos3A+cos5A=0

mars1129 [50]

<h2>Answer:</h2>

$A=\frac{\pi}{8}+\frac{n\pi}{4}or\ A=\frac{\pi}{2}+n\pi$

<h2>Step-by-step explanation:</h2>

<h3>Find angles</h3>

$cos3A+cos5A=0$

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<h3>Transform the expression using the sum-to-product formula</h3>

$2cos(\frac{3A+5A}{2})cos(\frac{3A-5A}{2})=0$

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<h3>Combine like terms</h3>

$2cos(\frac{8A}{2})cos(\frac{3A-5A}{2})=0\\\\ 2cos(\frac{8A}{2})cos(\frac{-2A}{2})=0$

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<h3>Divide both sides of the equation by the coefficient of variable</h3>

$cos(\frac{8A}{2})cos(\frac{-2A}{2})=0$

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<h3>Apply zero product property that at least one factor is zero</h3>

$cos(\frac{8A}{2})=0\ or\ cos(\frac{-2A}{2})=0$

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<h3>Cross out the common factor</h3>

$cos\ 4A=0$

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<h3>Solve the trigonometric equation to find a particular solution</h3>

$4A=\frac{\pi}{2}or\ 4A=\frac{3\pi}{2}$

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<h3>Solve the trigonometric equation to find a general solution</h3>

$4A=\frac{\pi}{2}+2n\pi \ or\\ \\ 4A=\frac{3 \pi}{2}+2n \pi\\ \\A=\frac{\pi}{8}+\frac{n \pi}{4\\}$

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<h3>Reduce the fraction</h3>

$cos(-A)=0$

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<h3>Simplify the expression using the symmetry of trigonometric function</h3>

$cosA=0$

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<h3>Solve the trigonometric equation to find a particular solution</h3>

$A=\frac{\pi }{2}\ or\ A=\frac{3 \pi}{2}$

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<h3>Solve the trigonometric equation to find a general solution</h3>

$A=\frac{\pi}{2}+2n\pi\ or\ A=\frac{3\pi}{2}+2n\pi,n\in\ Z$

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<h3>Find the union of solution sets</h3>

$A=\frac{\pi}{2}+n\pi$

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<h3>Find the union of solution sets</h3>

$A=\frac{\pi}{8}+\frac{n\pi}{4}\ or\ A=\frac{\pi}{2}+n\pi ,n\in Z$

<em>I hope this helps you</em>

5 0

2 years ago

A car averages 16.8 miles per gallon and uses 265 gallons traveling cross-country. What was the distance the car traveled

Norma-Jean [14]

1 gallon = 16.8 miles

265 gallons = 16.8 x 265 = 4452 miles

Answer: 4452 miles

8 0

3 years ago