3 years ago

PLEASE HELP!!!

Mathematics

1 answer:

Sveta_85 [38]3 years ago

8 0

I think it’s the first one

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The half-life of Radium-226 is 1590 years. If a sample contains 500 mg, how many mg will remain after 2000 years? Preview mg Giv

d1i1m1o1n [39]

Answer:

$a_{n}$ =209.09 mg

Step-by-step explanation:

given: material= radium

half life= 1590 years

initial mass $a_{0}$ =500mg

we know that to calculate the amount left we use

$a_{n}$ = $a_{0}$ $\left ( 0.5\right )^{n}$

$n=\frac{2000}{1590} = 1.2578$

therefore

$a_{n}$ = $500\times0.5^{1.2578}$

$a_{n}$ =209.09058407921 mg

$a_{n}$ =209.09 mg amount left after 2000 years

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4 years ago

There are 27 red or blue marvels in a bag. The number of red marbles is 5 less than 3 time the number of blue marbles. How many

BigorU [14]

Answer:

let R= red

let B= blue

R+B= 27

R=3B-5

3B-5+B=27

3B+B=27+5

4B=32

4B/4= 32/4

B=8

R= 3*8-5

R=24-5

R=19

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4 years ago

A car travels at 45 miles per hour how long did it travel in 4 hours?

wolverine [178]

Answer:

180 miles

Step-by-step explanation:

just multiple 45X4

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3 years ago

What number line shows the solution in the inequality -2x + 4 > 8

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Answer:

Step-by-step explanation:

x<=-2

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3 years ago

You find a car that is on sale for $13,000. It was originally $19,000. What is the percent change?

kipiarov [429]

Answer:

<em>( About ) % 31.58</em>

Step-by-step explanation:

Consider the procedure below;

$Increased Value = $ 19,000 - $ 13,000 = Difference ( $ 6000 ),\\\\Take Fraction of difference / Start Value = 6,000 / 19,000,\\( Percent ) = ( Around ) 31.58\\$

<em>Thus, solution; ( About ) % 31.58</em>

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3 years ago