IF 5^21 x 4^11 = 2 x 10^n what is the value of n?
11
21
22
23
32
The answer is 21 could somebody explain why?
11
21
22
23
32
The answer is 21 could somebody explain why?
This question has been answered many times before. But here goes:
10^n = (2*5)^n = (2^n)*(5^n). This means that:
2 * 10^n = 2*(2^n)*(5^n) = [2^(n+1)]*(5^n).
Now, look at the left side: 4^11 = (2^2)^11 = 2^22.
So you have:
(5^21)*(2^22) = [2^(n+1)]*(5^n).
This is why n = 21.
