B. Because the divisor, 4.2, has only value in the ones and tenths places, so we only have to multiply by 10 to get to 42, which is the whole number you need.
It neve mentions how much of his farm he uses, but assuming he uses all of it
area=base times height
given
base=4.2
height=3
area=4.2 times 3
area=12.6 square kilometers
answer is 12.6 km²
Answer:

Step-by-step explanation:
We want to simplify:

We rewrite as:

We split the radical sign to obtain:

Simplify the square root for the perfect squares to get:

Therefore the simplified form is: 
I DONT KNOW JUST STRAT WITH THE BEGGINIG OF THE SENTENCE
Answer:
0.02116402116
Or otherwise written as- 0.211