All categories

2 years ago

Please please please help me

Mathematics

1 answer:

Montano1993 [528]2 years ago

7 0

the answer is c i used a algebra calculator

You might be interested in

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

pedro goes to the gym every eight days but tennis is every twelve days if today is september 27 when will he do both again

Svetach [21]

October 21st, 24 days later

3 0

2 years ago

2. Three bells P, Q and R ring at intervals of 40, 48and 60 minutes respectively. If they ring together at 6.15 a.m. when will t

MAXImum [283]

They will ring again together at 10:15am. Because the common factor for 40, 48 and 60 is 240, which means 240 minutes, that equals to 4 hours. Hence 4 hours after 6.15am is 10.15am.

Hope this helps.

5 0

3 years ago

I ready scientific notation help

Airida [17]

The required value is $2\times10^9$

Step-by-step explanation:

Weight of ants = $4\times10^{-3}$

Weight of elephant= $8\times10^6$

We need to find, the total weight of about how many ants equals to the weight of an oversized elephant.

The equation given is:

$4\times10^{-3} \times a = 8\times10^6$

We need to find a:

Solving:

$4\times10^{-3} \times a = 8\times10^6\\a=\frac{8\times10^6}{4\times10^{-3}}\\if \,\,10^a/10^-b \,\,then\,\, 10^{a+b}\\a=2\times10^{6+3} \\a=2\times10^9$

So, the required value is $2\times10^9$

Keywords: Scientific Notation

Learn more about Scientific Notation at:

#learnwithBrainly

4 0

2 years ago

Paul got 15 out of 20 questions correct on his test. What percent of the questions did Paul get correct?

Dahasolnce [82]

75%

15/20 = 75/100 (you just have to multiply both top and bottom by five)

4 0

2 years ago

Read 2 more answers