If (a+b)=2,(b+c)=1, and (c+a)=3 then find a3+b3+c3

If (a+b)=2,(b+c)=1, and (c+a)=3 then find a3+b3+c3 ?

(a) 3

(b) 1

(c) 8

(d) 9

Sol:

a + b = 2

b + c = 1

c + a = 3

(a + b + c) = 3

Cube both sides

a³ + b³ + c³ + 3(a + b) (b + c) (c + a) = 27

a³ + b³ + c³ = 27 – 18

= 9