Use the definition of absolute value.
The absolute value is always non-negative. So if 
is already non-negative, 
is unchanged. But if is negative, then 
because multiplying by -1 makes it positive.
Now, if 
, then by the definition of absolute value,
V (cone) = (1÷3) × (r×r×h) л cm3
3 cone = 1 cylinder (if "h" and "r" is same)
There is two cone...
1st one: (1÷3) × 3×3×5 л cm3 = 15л cm3
2nd one: (1÷3) × 3×3×8 л cm3 = 24л cm3
15 + 24 = 39л cm3
2(10) +5(5)= 45
b=10 a=5
Plug in the values b and a.
