Add. Simplify, if possible. Help please.

A

Step-by-step explanation:

To add fractions, we want to make sure there is a common denominator. After that, we can add the numerator.

                [factor denominator]

     [multiply first fractioni by z-3 and second by z+3]

  [distribute by FOIL]

  [add]

This is the same as A. Therefore, A is our answer.

the solution is 12x-6y

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560