1 )If a + b + c = 0 ( a2 / bc ) + ( b2/ ca ) + ( c2 / ab ) = 3
2 ) Find the value of a ) 553 - 253 - 303
b ) 993
1) a + b + c = 0
(a2 / bc) + (b2 / ca) + (c2 / ab)
=( a3 + b3 + c3 ) / abc
If a + b + c = 0 , then a3 + b3 + c3 = 3abc
3abc / abc = 3
2) (55)3 + (-25)3 + (-30)3
a = 55 , b = - 25 , c = -30
a + b + c = 55 - 25 - 30 = 0
If a+ b + c = 0 then a3 + b3 + c3 = 3abc
Answer: 3 * 55 * ( - 25) * ( - 30)
= 123750.
3) (99)3
= (100 - 1)3
(100)3 - 13 - 3*100 * 1(99)
1000000 - 1 - 29700
= 970299