Question

If a^2 +b^2 + c^2 =40 and ab + bc + ca = 30, find the value of (a + b + c)^3

Answer 1

Step-by-step explanation:

a^2+b^2+c^2=40

2(ab+bc+ca)=2*30

a^2+b^2+c^2+2ab+2bc+2ca=40+60

=100

(a+b+c)^2=100

a+b+c=10

(a+b+c)^3=10^3=1000

Answer 2

Answer:

1000

Step-by-step explanation:

a^2+b^2+c^2 = 40

ab+bc+ca = 30

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

Above the values are mentioned..... substitute the values in above formula

(a+b+c)^2 =40+60

= 100

(a+b+c)^2 = 100

NOW,

(a+b+c) = 10

From above......

(a+b+c)^3 = (a+b+c)^2 ×(a+b+c)

=100×10

=1000

THIS IS THE REQUIRED ANSWER