(−2x^2+x+1)–(x^2–x+7)–(4x^2+2x+8)
Please explain

Step-by-step explanation:

First, remove the parenthesis.  Remember to distribute the negatives properly!

Next, rearrange the order of the numbers so it's easy to see the like terms.  Put the squared x's together, x's together, etc.  This step is optional but helpful.

Next, combine like terms.

Leave a note in the comments if you need me to elaborate on any steps.

7,24

step-by-step explanation:

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