1) number divided by itself. answer is always 1.
Or you can subtract the exponents. 12-12=0. y^0 = 1
2) answer is 1. Multiplying a fraction by it's denominator will leave only the numerator. An example of this rule: 1/2 * 2 = 1.
3) you're right! Something to the power of zero is always 1!
4) look back to the rule in answer 2. Remember, when multiplying, order doesn't matter. So, let's rearrange this.
2^2 * 1/2^2 * 2^5 * 1/2^5
See how the answer will be 1?
5) the answer here is also 1.
x/y * y/x = 1
Example: 2/3 * 3/2
(Two, divided by three, times three, times two. The part where we divide by three then multiply by three, those two actions cancel each other out. That leaves us with 'two divided by two'. That is obviously 1)