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2 years ago

PLEASE HELP I WILL MARK YOU BRAINIEST!!

Mathematics

1 answer:

Keith_Richards [23]2 years ago

5 0

Answer:
r = 9

The error happened when -3 was multiplied by -r in the first step, negative and negative makes a positive so it should have been
-18 + 3r= 9 in the second step.
Hope this helps :)

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3 4/7 minus 2 1/5 by rounding to the nearest half

mylen [45]

Answer:

$1 \frac{13}{35}$

Step-by-step explanation:

$3 \frac{4}{7} - 2 \frac{1}{5}$

you can solve for the fractions first, but you have to give them a common denominator

$\frac{20}{35}- \frac{7}{35}$

$= \frac{13}{35}$ which is in simplest form

then solve for the whole numbers

3-2=1

therefore, the answer is $1 \frac{13}{35}$

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3 years ago

What is 0.00277 scientific notation?

Harlamova29_29 [7]

2.77 × 10 ^ ( -3 ) is the answer

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3 years ago

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A person is standing 50 ft from a statue. The person looks up at an angle of elevation of 8 degrees when staring at the top of t

borishaifa [10]

The height of the statue is 19.5 feet.

Why?

We can solve the problem using trigonometric formulas. In this case, we are going to use the trigonometric formula of the tangent.

We know that the person is standing 50ft from the statue, so, it will be the base of the two triangles formed by both angles (elevation and depression)

Using the trignometric formula, we have:

First triangle:

$tg(\alpha )=\frac{h_{1}}{base} \\\\tg(8\°)=\frac{h_{1}}{50ft}\\\\0.14*50ft=h_1\\\\h_1=7ft$

Second triangle:

$tg(\alpha )=\frac{h_{2}}{base} \\\\tg(14\°)=\frac{h_{1}}{50ft}\\\\0.25*50ft=h_1\\\\h_1=12.5ft$

Now, the total height of the statue will be:

$TotalHeight=h_1+h_2=7ft+12.5ft\\\\TotalHeight=19.5ft$

Have a nice day!

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3 years ago

The length of a rectangle is 8 feet more than its width. If the width is increased by 4 feet and the length is decreased by 5 fe

alexgriva [62]

Let the width be x.

Length is 8 feet more than width. Length = x + 8

Area = x(x + 8)

width increased by 4, that is, (x + 4)
Length decreased by 5, (x + 8 - 5) = (x + 3)

Area = (x + 4)(x +3)

Area remains the same

x(x + 8) = (x+4)(x +3)

x² + 8x = x(x +3) + 4(x +3)

x² + 8x = x² +3x + 4x +12

x² + 8x = x² +7x +12 Eliminate x² from both sides

8x = 7x + 12

8x - 7x = 12

x = 12

Dimensions of original rectangle : x, x + 8

12, 12 +8 = 12, 20

Original rectangle is 20 feet by 12 feet

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3 years ago

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The depth of snow after n hours of a snowstorm is represented by the function f(n + 1) = f(n) + 0.8 where f(0) = 2.5. Which stat

Alja [10]

C

"When the storm began", it means it has been snowed for 0 hours, so n=0.
f(0)=2.5, thus the <span>depth of snow was 2.5 inches when the storm began.

f(n+1)=f(n)+0.8, so f(n+1)-f(n)=0.8
it means when the time increases by one hour, the depth of snow increases by 0.8 inches.</span>

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4 years ago

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