Answer: C
Step-by-step explanation:

Find the least common denominator of 4, 3, and 12.
4-3-12 | 3
4-1-4 | 4
1-1-1 |-------- 12
The first fractions needs to be multiplied by 3, and the second fraction, by 4

Solve;

Add the fractions with positive signs and subtract the one with negative sign.

Solve;

Simplify by 4;
16/4=4
12/4=3

I am almost 100% sure that this is the correct answer -1/32.
Answer:
The 1st Blank is: A pure substance, or simply a substance
The 2nd blank on the left is: Elements
The 3rd blank on the right is: Compounds
The 4th blank which is the second middle one is: A mixture
The 5th blank which is the bottom left one is: Heterogeneous mixture
The 6th blank which is the last one on the bottom right is: Homogeneous mixture
Look at the step-by-step explanation if you get confused at the bottom.
Step-by-step explanation:
The 1st Blank: I would just put a pure substance.
The 2nd blank on the left: They are three characteristics of elements but just put elements.
The 3rd blank on the right: They are three characteristics of compounds but just put compounds.
The 4th blank which is the second middle one is: The characteristics of a mixture but just put a mixture.
The 5th blank which is the bottom left one: Are the characteristics of a heterogeneous mixture but just put heterogeneous mixture.
The 6th blank which is the last one on the bottom right: Are the characteristics of a homogeneous mixture but just put homogeneous mixture.