SOLUTION: Prove these identities. a) (a+b+c)(ab+bc+ca)−abc= (a+b)(b+c)(c+a) b) (ax+by)^2 + (ay−bx)^2 +c^2(x^2 +y^2)= (x^2 +y^2)(a^2 +b^2 +c^2) Thank you so much :)

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Question 1139327: Prove these identities.
a) (a+b+c)(ab+bc+ca)−abc= (a+b)(b+c)(c+a)
b) (ax+by)^2 + (ay−bx)^2 +c^2(x^2 +y^2)= (x^2 +y^2)(a^2 +b^2 +c^2)
Thank you so much :)

Answer by MathLover1(20849)   (Show Source): You can put this solution on YOUR website!
a)

manipulate left side

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b.)

manipulate left side:

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