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3 years ago

Math help please i will mark brainliest!!!!!

Mathematics

1 answer:

mel-nik [20]3 years ago

4 0

Answer:

The second choice is the correct one.

Step-by-step explanation:

20x^4 - 45x^2

GCF is 5x^2, so the factors are:

5x^2( 4x^2 - 9)

Now 4x^2 - 9 is the differencr of 2 squares:

4x^2 - 9 = (2x + 3)(2x - 3)>

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Jim and Mark start at the same place jim walks 15ft West and Mark Walks 12 feet North how far apart are the boys when they finis

r-ruslan [8.4K]

The two points where they end and the point where they start form a right triangle, one leg is 12, the other leg is 15, you need to find the hypotenuse.
use the Pythagorean theorem: 12²+15²=c²
c≈19
they are about 19 feet apart.

3 0

3 years ago

2 taps A and B can fill a swimming pool in 3 hours. If turned on alone, it takes tap A 5 hours less than tap B to fill the same

vazorg [7]

Answer:

Tap A will take 2 hours and tap B will take 6 hours to fill the tank when turned on alone.

Step-by-step explanation:

Let tap B fills the pool alone in the time = x hours

So in one hour part of pool will be filled = $\frac{1}{x}$

Another tap A when turned on, it takes time to fill the pool = x-5 hours

So in one hour part of the same pool filled = $\frac{1}{x-5}$

Now both the taps A and B are turned on then time taken to fill the pool = 3 hours.

Part of the pool filled in one hour by both the taps = $\frac{1}{3}$

Now we form an equation

Part of pool filled in one hour by tap A + Part of pool filled in one hour by tap B = Part of pool filled in one hour by both the taps when turned on

$\frac{1}{(x-5)}+\frac{1}{x}=\frac{1}{3}$

$\frac{x-5+1}{x(x-5)}=\frac{1}{3}$

$\frac{x-4}{x(x-5)}=\frac{1}{3}$

3(x - 4) = x(x - 5)

x² -5x = 3x - 12

x² - 8x + 12 = 0

x² - 6x - 2x + 12 = 0

x(x - 6) - 2(x - 6) = 0

(x -2)(x - 6) = 0

x = 2, 6 hours

We will take higher value of x as x = 6 hours for tap B.

Time taken by tap A = 6 - 4 = 2 hours.

Therefore, Tap A will take 2 hours and tap B will take 6 hours to fill the tank when turned on alone.

4 0

3 years ago

Can you help me solve 13 please 100 points

hoa [83]

Answer: A. 70

Step-by-step explanation:

95 + 90 + 85 + 80 + 70 = 420, then divide that by 5 equals 84

4 0

3 years ago

Read 2 more answers

at five pm a four foot mailbox casts a shadow six feet long at the same time a tree cast a shadow 36 feet Long bhow tall is the

Andrej [43]

So the 4ft mailbox’s shadow was six feet. That 2ft longer. According to my logic if the tree had a showdown of 36ft we subtract 2ft. The trees actual size is 34ft.

I might be wrong don’t hate me :(

5 0

3 years ago

Someone help I don't get it

Gemiola [76]

The answer is the first choice.

6 0

3 years ago