Answer:
A
and
D
Step-by-step explanation:
Because if you simplify the equation theb you get 8x+4 therefore D is equivalent to it. A is also equal to D which make it equivalent to the equation as well.
It's closed under addition. You can take any two natural numbers you want, add them up and you'll get some other natural number (eg: 3 and 5 ---> 3+5 = 8)
it's not closed under subtraction. Sure 5-3 = 2 is a natural number but 3-5 = -2 is not a natural number
so that leads us to the answer being choice B
You must multiply the all the numerators first. This is 8 x 6 x 1 = 48. Therefore you know 48 will be the top number. Now you multiply the denominators 15 x 5 x 3 = 225. Therefore the answer will be 48/225. However you can simply this fraction. Now you must think of a number that both 48 and 225 are divisible by, in this case it is 3. Therefore the answer is 16/75.
