15/8-4/5/1+(15/8)(4/5)

PLEASE HELP ME FAST I NEED HELP PLEASE

ziro4ka [17]

Answer:

2 - Ratio B

3 - Ratio B

4 - Ratio B

5 - Ratio A

7 0

3 years ago

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-8x - 8y = 0 and -5x - 4y = 5. Solve the system of equations

Rashid [163]

Answer:

x=-5, y=5 or (-5,5)

Step-by-step explanation:

We can do elimination with this

this means we should first multiply -5x-4y=5 by 2

this would make it -10x-8y=10

we can now subtract this from the original equation

-8x-8y=0 - (-10x-8y=10)

the ys would cancel out

so this would equal

2x=-10

x=-5

now we can plug this back into the equation to find y

-8(-5)-8y=0

40-8y=0

-8y=-40

y=5

4 0

3 years ago

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The half-life of a certain radioactive element is 35 hours. If there are 904 grams of this element, how much will be left after

Cloud [144]

<h3>Answer: 226 grams</h3>

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Explanation:

The half-life is 35 hours. This means every 35 hours, the amount of the substance is cut in half. If we started with 100 grams, then 35 hours later, we will have 50 grams. Then another 35 hours later we will then have 25 grams, and so on.

In this case, we start with 904 grams and follow this sequence:

904, 452, 226, 113, ...

Each term is cut in half. Going from term to term it takes 35 hours each. The third term 226 is the result of waiting two half-lives, which is 2*35 = 70 hours that have elapsed total.

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If you want to use a formula, then it would be

$y = A*\left(\frac{1}{2}\right)^{x/H}$

where,

H = half-life duration (in this case, it is 35)

A = starting amount (which is 904 in this case)

x = amount of time that has elapsed (we will plug in x = 70)

y = final amount after x units of time has elapsed

note that x and H must have the same time unit. Both are in terms of hours in this case.

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So we will plug A = 904, x = 70, H = 35 into the formula to get...

$y = A*\left(\frac{1}{2}\right)^{x/H}\\\\y = 904*\left(\frac{1}{2}\right)^{70/35}\\\\y = 904*(0.5)^{2}\\\\y = 904*(0.25)\\\\y = 226\\\\$

We see that x = 70 leads to y = 226. This means after 70 hours, there is 226 grams of the material left.

4 0

3 years ago

Leila says that 75% of a number will always be greater than 50% of any other number.

Gemiola [76]

That is not correct, it depends on the numbers you are referring to. For instance, 75% of 100 is 75, but 50% of 1000 is 500, so in this case the 50% of a number is higher than 75% of another number. Although, is true that 75% is higher than 50% of the same number always.

3 0

3 years ago

How do I write 76543 to the -4 power in simplest form?

Reika [66]

<u>Answer:</u>

<u />

So, I don't know how other teachers taught you, but I have a trick.

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

<u />

Step 1:

Solve $76543^{4}$

$76543^{4}$ = 34325898917194100000

Step 2:

Now put 34325898917194100000 under 1, like this:

$\frac{1}{34325898917194100000}$

<em>Note: Whenever you have a negative power, the result of the exponent will always be a fraction under 1.</em>

<em />

Step 3:

Add the negative:

$\frac{1}{34325898917194100000}$ becomes:

$-\frac{1}{34325898917194100000}$

Your answer is $-\frac{1}{34325898917194100000}$

I hope this helps!

<h2><u>PLEASE MARK BRAINLIEST!</u></h2>

4 0

3 years ago