Which of these are written in scientific notation

A properly written number in scientific notation has the form:
+/- A*10^n
where +/- is either plus or minus
A is a decimal number (or integer) where 1<= A < 10
and n is a positive or negative integer.

According to these rules, 
120,000,000 is written in scientific notation as
1.2 * 10^8
so we need to move the decimal point 8 places to the left and multiply by 10^8.

Answer:

$4034.40

step-by-step explanation:

the perimeter of the field is the sum of the lengths of the four sides:

47 yd + 158 yd + 47 yd + 158 yd = 410 yd

the cost of 3 ft (1 yd) of fence is 3×$3.28 = $9.84.

so the cost of jake's wood perimeter fance is

(410 yd) × ($9.84 /yd) = $4034.40

Abcd stupid son of a bitxh