I really need help. Can you please show your work too.

Step-by-step explanation:

You just combine common variables.

8a^5 -4

3a^5 + a -2

11a^5 + a -6

The solution to the first is 11a^5+a-6.

The second:

3x^2 -2x + 1

-x^2 + 3x + 1

2x^2 + x + 2

2x^2+x+2

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