Answer:
f(x + 1) = 3x² + 5x + 7
Step-by-step explanation:
To find f(x + 1), substitute x = x + 1 into f(x), that is
f(x + 1) = 3(x + 1)² - (x + 1) + 5 ← expand (x + 1)² using FOIL
= 3(x² + 2x + 1) - x - 1 + 5 ← distribute parenthesis by 3
= 3x² + 6x + 3 - x - 1 + 5 ← collect like terms
= 3x² + 5x + 7
Answer:
P(t) = 27000 * (1/9)^(t/4)
Step-by-step explanation:
This problem can me modelled with an exponencial formula:
P = Po * (1+r)^t
Where P is the final value, Po is the inicial value, r is the rate and t is the amount of time.
In this problem, we have that the inicial population/value is 27000, the rate is -8/9 (negative because the population decays), and the time t is in months, so as the rate is for every 4 months, we use the value (t/4) in the exponencial.
So, our function will be:
P(t) = 27000 * (1-8/9)^(t/4)
P(t) = 27000 * (1/9)^(t/4)
Answer:
P(6) = 0.6217
Step-by-step explanation:
To find P(6), which is the probability of getting a 6 or less, we will need to first calculate two things: the mean of the sample (also known as the "expected value") and the standard deviation of the sample.
Mean = np
Here, "n" is the sample size and "p" is the probability of the outcome of interest, which could be getting a heads when a tossing a coin, for instanc
So, Mean = n × p = (18) ×(0.30) = 5.4
Next we we will find the standard deviation:
Standard Deviation = 
n = 18 and p = 0.3 "q" is simply the probability of the other possible outcome (maybe getting a tails when flipping a coin), so q = 1 - p
Standard Deviation =
= 1.944
Now calculate the Z score for 6 successes.
Z = ( of successes we're interested in - Mean) ÷ (Standard Deviation)
=(6-5.4) ÷ (1.944) = 0.309
we have our Z-score, we look on the normal distribution and find the area of the curve to the left of a Z value of 0.309. This is basically adding up all of the possibilities for getting less than or equal to 6 successes. So, we get 0.6217.
This are the right steps
Step 1: first you divide the both size by 7 because there is 7 a's
7a/7 = 28/7
Step 2: You solve the equation
7a/7= a. 28/7 = 4
So, the answer is a = 4
not 7 = 4