lukeposada wrote:Need some help understanding this one:
The value of (10^8 - 10^2)/(10^7 - 10^3) is closest to which of the following?
a - 1
b - 10
c - 10^2
d - 10^3
e - 10^4
the answer is b
Here's an alternate approach.
Whenever you see things being added or subtracted, ask yourself:
What is the GCF (the greatest common factor) that can be factored out of each term?
10^2 is the GCF of 10^8 and 10^2:
10^8 - 10^2
= 10^2(10^6 - 1)
= 10^2(10^6) approximately
= 10^8 approximately
10^3 is the GCF of 10^7 and 10^3:
10^7 - 10^3
= 10^3(10^4 - 1)
= 10^3(10^4) approximately
= 10^7 approximately
So (10^8 - 10^2)/(10^7 - 10^3)
= 10^8/10^7 approximately
= 10 approximately
The correct answer is B.
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