3 years ago

Solve the system by substitution. y = 7x – 20 y = 2x

Mathematics

1 answer:

g100num [7]3 years ago

4 0

Answer:

x=4 y=8

Step-by-step explanation:

Solve for the first variable in one of the equations, then substitute the result into the other equation

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How many times does 1/3 go into 1/18?

Orlov [11]

6 is the answer 18 divided by 3 equals to 6 so that’s the answer

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3 years ago

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A 46 gram sample of a substance that is used to sterilize surgical instruments has a k-value of 0.1374. Find the substance's hal

mars1129 [50]

Answer:

$t=5.0days$

Step-by-step explanation:

Using the formula for the exponential decay that is $N=N_{0}e^{-kt}$ , we have N= $\frac{1}{2}{\times}46=23$ , $N_{0}=46$ and k=0.1374.

Thus, $N=N_{0}e^{-kt}$ becomes

$23=46{\times}e^{-0.1374t}$

$\frac{23}{46}=e^{-0.1374t}$

$\frac{1}{2}=e^{-0.1374t}$

Taking log on both sides, we get

$ln(\frac{1}{2})={-0.1374t}$

$t=\frac{ln\frac{1}{2}}{-0.1}$

$t=\frac{-0.6931}{-0.1374}$

$t=5.0days$

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3 years ago

Alexander invested $320 in an account paying an interest rate of 1.5% compounded annually. Assuming no deposits or withdrawls we

boyakko [2]

Answer:

The amount is $418.35 and the interest is $98.35

Step-by-step explanation:

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3 years ago

Can anyone help me figure out the answer to this

Alex17521 [72]

3x-11=17-4x add 4x to both sides

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3 years ago

Troy is writing a book of short stories. It is his

joja [24]

Answer:

91 short stories

Step-by-step explanation:

You just add 1 + 2 + 3 + 4 + 5 + 6... all the way to 13, and then at the end of 16 months, Troy still only wrote 91 stories since he only wrote them up until 13 months, and then stopped afterwards.

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2 years ago