Answer:
8 hours
Step-by-step explanation:
5 - 1 = 4 grams
10% of 5 = 0.5 grams per hour
4/0.5 = 8 hours
This is a problem of Difference-of-squares. We know that for a difference of squares

the factorization is given by:

To learn this you need to remember that a <em>difference</em> means <em>subtraction.</em> So applying those concepts we can solve this problem step by step.
Applying distributive property:

Applying distributive property again:

Simplifying:
<em>The correct answer is C</em>
Answer:
B, D
Step-by-step explanation:
Answer: A proper subset is one that contains few elements of the original set whereas an improper subset, contains every element of the original set along with the null set.