8. in many courts, 12 jurors are chosen from a pool of 30 perspective jurors.
a. in how many ways can 12 jurors be chosen from the pool of 30 perspective jurors?
b. once the 12 jurors are selected, 2 alternates are selected. the order of the alternates is specified. if a selected juror cannot complete the trial, the first alternate is called on to fill
that jury spot. in how many ways can the 2 alternates be chosen after the 12 jury members have been chosen?

The number of ways to select 12 jurors are 86493225.

The number of ways to select 2 alternates are 306.

Step-by-step explanation:

Consider the provided information.

In many courts, 12 jurors are chosen from a pool of 30 perspective jurors.

Part (A):  In how many ways can 12 jurors be chosen from the pool of 30 perspective jurors?

Since order doesn't matter so we will use combination.

Use the formula for combination

Substitute n=30 and r=12 in above formula.

Hence, the number of ways to select 12 jurors are 86493225.

Part (B) Once the 12 jurors are selected, 2 alternates are selected. The order of the alternates is specified. If a selected juror cannot complete the trial, the first alternate is called on to fill  that jury spot. In how many ways can the 2 alternates be chosen after the 12 jury members have been chosen?

Here 12 jury members have been chosen, so 30-12=18 perspective jurors are left.

From 18 perspective jurors we need to select 2 alternates.

Since the order of the alternates matter so we will use permutation:

The formula for permutation is:  

Substitute n=18 and r=2 in above formula.

Hence, the number of ways to select 2 alternates are 306.

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10

answer: -2+√x,-2-√x

i hope this , i don't know if you're looking for a pair or not.