Well I am going to guess and i don't know if it right but 156.25ml
Answer:

Step-by-step explanation:
In order to add or subtract numbers in scientific notation, the powers of ten must have the same exponent. In this caes the diameter of an average human body cell is a power of -4 and the diameter of a plant cell is a power of -3. In order to add them, we can move the decimal over for the body cell diameter:

Add the two values: 
That would be total collected over w weeks is 6w - 14
10 and 2.
GCF of 2 is 10 and 2?