Solve log4 (y – 9) + log4 3 = log4 81.

y = 36

Step-by-step explanation:

log4 (y – 9) + log4 3 = log4 81.

We know from the property of logs that if the bases are the same, when we subtract logs, we can divide what is inside

loga (b) + loga (b) = loga (b*c)

Lets simplify the expression log4( (y-9)*3) = log4 (81)

Since the bases are the same, what is inside the parentheses on the left hand side  must be equal to what is inside the parentheses o the right hand side

(y-9)*3 = 81

Divide each side by 3

(y-9)*3 /3= 81/3

y-9 = 27

Add 9 to each side

y-9+9 = 27+9

y = 36

(x3 + 6x2 + 2x - 6) • (x - 1)

step-by-step explanation:

polynomial long division :

3.2     polynomial long division

dividing :   x4+5x3-4x2-8x+6

                              ("dividend")

by         :     x-1     ("divisor")

dividend     x4   +   5x3   -   4x2   -   8x   +   6

- divisor   * x3     x4   -   x3            

remainder         6x3   -   4x2   -   8x   +   6

- divisor   * 6x2         6x3   -   6x2        

remainder             2x2   -   8x   +   6

- divisor   * 2x1             2x2   -   2x    

remainder               -   6x   +   6

- divisor   * -6x0               -   6x   +   6

remainder                     0

quotient :   x3+6x2+2x-6   remainder:   0

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.