Answer:
88
Step-by-step explanation:

The mean would be the sum of all the math quiz grades divided by the number of quizzes taken.
Solve for x:



Thus, Allen needs at least an 88 to obtain a mean of at least 90.
I got F^-1(x) = x/4 + 4/9.
I believe the answer is B.
Answer:
The mass of the radioactive sample after 40 minutes is 12.8 g.
Step-by-step explanation:
The mass of the sample can be found by using the exponential decay equation:

Where:
N(t): is the amount of the sample at time t =?
N₀: is the initial quantity of the sample = 120 g
t = 40 min
λ: is the decay constant = 0.056 min⁻¹
Hence, the mass of the sample after 40 min is:

Therefore, the mass of the radioactive sample after 40 minutes is 12.8 g.
I hope it helps you!
Answer:
9(7j)/63j
Step-by-step explanation:
9(2j+5j)
= 9(7j)
= 63j
Answer:
1) Let's consider the first case with the number 0 the oppose is also 0 and we have that 0-0=0 so then applies
2) Now let's consider any real number a no matter positive or negative we will have that:

Or in the other case:

So then we can conclude that the expression is a general rule and is true
Step-by-step explanation:
For this case we can verify if the following expression is true or false:
The sum of x and it’s opposite is always zero?
If we want to proof this we need to show that for any number is true.
1) Let's consider the first case with the number 0 the oppose is also 0 and we have that 0-0=0 so then applies
2) Now let's consider any real number a no matter positive or negative we will have that:

Or in the other case:

So then we can conclude that the expression is a general rule and is true