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2 years ago

1. Expand 7(3x-4y)

Mathematics

1 answer:

Lesechka [4]2 years ago

3 0

9514 1404 393

Answer:

21x -28y
30 minutes

Step-by-step explanation:

1. The distributive property tells you the factor outside parentheses multiplies each of the term inside parentheses.

7(3x -4y) = 7·3x -7·4y = 21x -28y

2. Time, speed, and distance are related by ...

time = distance/speed

time = (20 mi)/(40 mi/h) = 1/2 h = 30 minutes

The drive takes 30 minutes.

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Convert from rectangular to polar coordinates: note: choose rr and θθ such that rr is nonnegative and 0≤θ<2π0≤θ<2π (a)(9,0

DochEvi [55]

Answer:

Step-by-step explanation:

Convert rectangle (x , y) to polar coordinates ( r , θ)

$x=r \cos \theta, y= r \sin \theta$

$r=\sqrt{x^2+y^2} , \theta =tan^-^1 (\frac{y}{x} )$

a) converts (9, 0) to polar coordinates ( r , θ)

$r=\sqrt{x^2+y^2} \\\\=\sqrt{9^2+0} \\\\=9$

$\theta= \tan^-^1 (\frac{0}{9} )\\\\=0$

b) Convert $(18,\frac{18}{\sqrt{3} } )$ to polar coordinates ( r, θ)

$r = \sqrt{18^2+(\frac{18}{\sqrt{3} })^2 } \\\\=\sqrt{324+108} \\\\=\sqrt{432}$

$\frac{x}{y} \theta = \tan^-^1(\frac{\frac{18}{\sqrt{3} } }{18} )\\\\= \tan ^-^1(\frac{1}{\sqrt{3} } )\\\\= \frac{\pi}{6}$

c) converts (-5, 5) to polar coordinates ( r , θ)

$r =\sqrt{(-5)^2+(5)^2} \\\\=\sqrt{50} \\\\=5\sqrt{2}$

$\theta=\tan^-^1(\frac{5}{-5} )\\\\= \tan^-^1(-1)\\\\=\frac{3\pi}{4}$

d) converts (-1, √3) to polar coordinates ( r , θ)

$r=\sqrt{(-1)^2+(\sqrt{3})^2 } \\\\= \sqrt{4} \\\\=2$

$\theta=\tan^-^1(\frac{\sqrt{3} }{-1} )\\\=\tan^-^1(-\sqrt{3} )\\\\=\frac{2\pi}{3}$

$= \frac{2\pi}{\sqrt{3} }$

6 0

3 years ago

Do the data in the table represent a direct variation or inverse variation? Write an equation to model the data in the table?

notsponge [240]

Based on the given data; the table represent an inverse variation and the equation that model the data in the table is y = 8/x

<h3>Variation</h3>

Direct variation

y = k × x

4 = k × 2

4 = 2k

k = 4/2

k = 2

when y = 2 and x = 4

y = k × x

= 2 × 4

y = 8

Indirect variation

y = k/x

4 = k / 2

8 = k

when y = 2 and x = 4

y = k/x

2 = k/4

2 × 4 = k

k = 8

So,

y = k/x

y = 8/x

Learn more about variation:

brainly.com/question/6499629

#SPJ1

5 0

2 years ago

Find the measures of the exterior angles of the polygon.

Len [333]

Step-by-step explanation:

180 - 34 = 146

one angle is a right angle, angle across it is 146, 360 - 90 - 146 = 124

divide that by two to get the measures of the remaining two angles (62 degrees)

180 - 62 = x

118 = x

4 0

2 years ago

Read 2 more answers

Plss answer my question now i need it this friday

professor190 [17]

Hello! i can do the first word problem

first we need to divide 600/3 which is 200.
therefore we can infer that he does 200 letters an hour and we can solve the problem with this

200 x 7 = 1400 letters an hour

6 0

2 years ago

{(0, 2), (3, 3), (8, 7), (2, 2), (3,9) }

k0ka [10]

Hey!!!

Here's your answer:

<h3>Domain:{(0,2,3,8)}</h3><h3>Range:{(2,3,7,9)}</h3>

Hope it will help u. 

<h3>have a great day .....</h3>

5 0

3 years ago