Answer: D. 
Step-by-step explanation:
Using exponent rules an exponent to the power of a number will multiply by each other.
So the -4 and -9 will multiply.
The 6 in the numerator will now have a positive exponent of 36.

Now we can divide and when we do so the exponents will subtract from each other.
So 36 - 6 = 30
And the base of 6 does not change.
The simplified form is 
the first solution is 20% acid, and say we'll be using "x" liters, so how many liters of just acid are in it? well 20% of "x" or namely 0.2x. Likewise for the 60% acid solution, if we had "y" liters of it, the amount of only acid in it is 0.6y.


Answer:
3/16
Step-by-step explanation:
3/8 * 4/8= 3/16
3/8= 3 pens out of 8 items
4/8= 4 crayons out of 8 items
You add the previous 2 numbers so the answer would be 162