Strontium 90 is a radioactive material that decays according to the function Upper A (t )equals Upper A 0 e Superscript negative 0.0244 t Baseline commaA(t)=A0e−0.0244t, where Upper A 0A0 is the initial amount present and A is the amount present at time t (in years). Assume that a scientist has a sample of 500500 grams of strontium 90. (a) What is the decay rate of strontium 90?

Decay rate K = -2.44%

Step-by-step explanation:

From the question, we want to know the decay rate of strontium 90

Mathematically, this is accessible from its decay equation

From the decay equation, we can see that that ;

At = Ao e^-0.0244t

Generally, the decay equation of a radioactive sample can be written as

At = Ao e^-kt

where K represents the decay constant

From the equation, we can see that;

k = 0.0244 which when represented as a percentage is 2.44%

Since it’s a decay we can say that the decay rate is -2.44%

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

i think c. but don't trust it.

step-by-step explanation: