Question

If a+b+c=9 and a²+b²+c²=35 find value of a²+b²+c²-3abc​

Answer 1

Step-by-step explanation:

given-

a+b+c = 9. .......…..............(1)

a^2+b^2+c^2 = 35...........(2)

Squaring both the sides in (1)

(a+b+c)^2 = 9^2

a^2+b^2+c^2+2(ab+bc+ca) = 81

35+2(ab+bc+ca) = 81 (from 2)

2(ab+bc+ca) = 81-35

2(ab+bc+ca) = 46

ab+bc+ca = 46/2

ab+bc+ca = 23....................(3)

a^3+b^3+c^3-3abc =

(a+b+c)(a^2+b^2+c^2-ab-bc-ca)

(9)(35-23) (from 1, 2 and 3)

9*12

108 ANS

Answer 2

Hope this answer helps you