First off, nicely done on the exponents. You'd be surprised on how bad some look ,:D
a)

b)
If you subtract -9-21 and 36-56
Answer:

Step-by-step explanation:
Answer:

Step-by-step explanation:
step 1
<u>Find the volume of the tank</u>
we know that
The volume of a cylinder (water tank) is equal to

in this problem we have
-----> the radius is half the diameter
substitute

step 2
Find the cost

Answer:
The completed reaction is
CaCO3 + 2 HCl → (Ca+2 + 2 Cl-)aq + H2O + CO2↑