Question

Ab (a²+b²+c²)-bc(c²-a²-b²)+ca(a²+b²-c²)

Answer 1

ANSWER

Answer is 29

Step-by-step explanation:

given that a+b+c=9

squaring on both sides

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

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

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

81-2×26

=81-52

=29

I hope you understand