In which situation would the appropriate unit of measure be kilometers?

You could use kilometers when you're describing how far away your neighbor is. If they lived down the street you could say they lived 2 kilometers away. Or when you're measuring a height as well.  

Step-by-step explanation:

Kilometer is 1093.61 yards so yard is 3 feet. So a reasonable answer would be your neighbor, or someone who lived a little bit away from you. You could also use it to describe height. This is a weird example but usually when they measure tsunamis they use kilometers to measure the height.

Hoped I helped

~ Ria

a4 - 3a2 - 1

step-by-step explanation:

step   1   :

equation at the end of step   1   :

  ((a4) -   3a2) -   1

step   2   :

trying to factor by splitting the middle term

2.1     factoring   a4-3a2-1  

the first term is,   a4   its coefficient is   1 .

the middle term is,   -3a2   its coefficient is   -3 .

the last term, "the constant", is   -1  

add all the numbers and check the ones place.

the answer is 486. as the ones place is more than 4, the estimation will be the next 10 ie, 490