Question

Which statement is true about the value of (5^−n)(5^n)?
For n<0, the value of the expression is greater than 1.
For all n, the value of the expression is 0.
For n<0, the value of the expression is less than 1.
For all n, the value of the expression is 1.

Answer 1

For this one, you just have to test out numbers

For the first one it says, for n < 0, the value is greater than 1.

So lets say n = -5 for example

(5^-5)(5^5) = 1. 1 is not greater than 1, so that one's out

The second one says for all n, the answer is 0.

Well, we just saw n = 5 turns out to be 1 and 1 does not equal 0, so that one's out too

For the third one, it says for all n<0, its less than 1

Again 1 is not less than 1, so that's wrong

Now we have D. For all values n, it equals 1

1 does = 1, so lets try n =10 to be safe

(5^-10)(5^10) indeed equals 1, so the answer is D, the last choice