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3 years ago

13

the only black pens and green pens in a box the ratio of a number of black pens in the box to the number of green pens in the bo

x is to 5 what fraction of pens are black

1 answer:

eduard3 years ago

4 0

Fraction of black pens = 2/ (2 + 5) = 2/7 answer

You might be interested in

If g(x)=6/(x-3) find g(5)

alexandr1967 [171]

Answer:

the answer is 3

Step-by-step explanation:

function notation is the way a function is written.

6 0

2 years ago

Helppppppppppppppppppppppppp

Solnce55 [7]

Set the two expressions equal to each other.

7x + 3 = 9x

Simplify, isolate the x, subtract 7x from both sides

7x (-7x) + 3 = 9x (-7x)
3 = 2x

Set the equation = 0, subtract 3 from both sides

3 (-3) = 2x (-3)

0 = 2x - 3

2x - 3, or D, should be your answer

hope this helps

8 0

3 years ago

Element X is a radioactive isotope such that its mass decreases by 26% every day. If an experiment starts out with 810 grams of

ioda

Answer:

The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.

The function to represent the mass of the sample after t days is $A(t) = 810(0.74)^t$

Step-by-step explanation:

Exponential equation of decay:

The exponential equation for the amount of a substance is given by:

$A(t) = A(0)(1-r)^t$

In which A(0) is the initial amount and r is the decay rate, as a decimal.

Hourly rate of change:

Decreases 26% by day. A day has 24 hours. This means that $A(24) = (1-0.26)A(0) = 0.74A(0)$ ; We use this to find r.

$A(t) = A(0)(1-r)^t$

$0.74A(0) = A(0)(1-r)^{24}$

$(1-r)^{24} = 0.74$

$\sqrt[24]{(1-r)^{24}} = \sqrt[24]{0.74}$

$1 - r = (0.74)^{\frac{1}{24}}$

$1 - r = 0.9875$

$r = 1 - 0.9875 = 0.0125$

The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.

Starts out with 810 grams of Element X

This means that $A(0) = 810$

Element X is a radioactive isotope such that its mass decreases by 26% every day.

This means that we use, for this equation, r = 0.26.

The equation is:

$A(t) = A(0)(1-r)^t$

$A(t) = 810(1 - 0.26)^t$

$A(t) = 810(0.74)^t$

The function to represent the mass of the sample after t days is $A(t) = 810(0.74)^t$

5 0

2 years ago

6000 increased by 145%

Lisa [10]

Your question would be clearer if written as "What is 145% of 6000?"

1.45(6000) = 8700

8 0

3 years ago

Can someone help me find the value of x for the figures given ? Thanks!

stealth61 [152]

I hope this helps you

4 0

2 years ago