**Answer:**

an = 12 + 6(n-1)

**Step-by-step explanation:**

The formula for an arithmetic sequence is

an = a1+d(n-1)

where a1 is the first term and d is the common difference

a1 =12

To find d take the second term and subtract the first term

18-12 = 6

Check with the third term and the second term

24 -18 = 6

We add 6 each time

d= 6

an = 12 + 6(n-1)

**Answer:**

9

**Step-by-step explanation:**

just add

**Answer:**

Option A is correct, i.e. 4.5*10^-3

**Step-by-step explanation:**

To write scientific notations:-

1. The first digit should be non-zero.

2. The decimal representation should be a number greater than 1 and less than 10.

3. The exponent representation should be in form of 10's power.

Checking given options:-

B. 14.5*10^2

Given option B has decimal representation greater than 10, so it is NOT correct.

C. 0.78*10^-6

Given option C has decimal representation less than 1, so it is NOT correct.

D. 5.7*4^8

Given option D has exponent representation NOT in form of 10's power, so it is NOT correct.

<u>Checking option A:- 4.5*10^-3</u>

Given option A has decimal representation between 1 and 10. Also it has exponent representation in form of 10's power.

**Hence, option A is correct, i.e. 4.5*10^-3**

$9 a day for 8 days.

So, for every day that went by they earned $9. In other words the answer is the Amount of Money Earned per day multiplied by the number of days!

So!

$9 * 8days

Or you can also think of it as this:

9+9+9+9+9+9+9+9

**Our answer comes out to be 72!**