Question

(3a-2b)³+(2b-5c)³+(5c-3a)³

Answer 1

The answer is 0 (zero) 
I'm assuming ^ is the multiplication sign. 

First bracket is (3a-2b)^3 
Open the bracket--- 3a^3=9a, 2b^3=6b therefore; 9a-6b 

Second Bracket is (2b-5c)^3 
Open the bracket--- 2b^3=6b, 5c^3=15c therefore; 6b-15c 

Third Bracket is (5c-3a)^3 
Open the bracket--- 5c^3=15c, 3a^3=9a therefore; 15c-9a 

Put back together; 
9a-6b+6b-15c+15c-9a 

Collect like terms; 
9a-9a-6b+6b-15c+15c=0