Question

If a + b + c = 9 and a² + b² + c² = 35 , find the value of a³ + b³ + c³ - 3abc .
Anybody help ...

Answer 1

Answer:

108

Step-by-step explanation:

Using formula,

(a+b+c)

2

=a

2

+b

2

+c

2

+2(ab+bc+ca)

9

2

=35+2(ab+bc+ca)

2(ab+bc+ca)=81−35=46

(ab+bc+ca)=23

using formula,

(a

3

+b

3

+c

3

)−3abc=(a

2

+b

2

+c

2

−ab−bc−ca)(a+b+c)

a

3

+b

3

+c

3

−3abc=(35−23)×9=9×12=108

Answer 2

Step-by-step explanation:

(a+b+c)²=9²=81a²+b²+c²+2ab+2bc+2ca=81a²+b²+c²+2ab+2bc+2ca-(a²+b²+c²)=81-352ab+2bc+2ca=462