Answer:
the abstract science of number, quantity, and space, either as abstract concepts ( pure mathematics ), or as applied to other disciplines such as physics and engineering ( applied mathematics ).
Answer:
Multiply by every term in the second expression:
Multiply by every term in the second expression.
Multiply 1 by every term in the second expression.
Now we take those nine terms (everything on the right side of those above equations) and add 'em all up
Answer:
Part 1) 
Part 2) There are about 
Step-by-step explanation:
Part 1) we know that
1 month=4 weeks
Let
x------> the number of hours of practice for three months
so
Convert months to weeks
3 months=3(4)=12 weeks
using proportion

that means------> In three months (12 weeks) the pianist practice 180 hours
Part 2)
Let
x------> the number of bass
y------> the number of catfish
we know that
Using proportion

There are about 