#### Question

Show that (a - b)(a + b) + (b - c) (b + c) + (c - a) (c + a) = 0

#### Solution

L.H.S = (a - b) (a + b) + (b - c) (b + c) + (c - a) (c + a)

= (a^{2} - b^{2}) + (b^{2} - c^{2}) + (c^{2} - a^{2}) = 0 = R.H.S

Is there an error in this question or solution?

Solution Show that (A - B)(A + B) + (B - C) (B + C) + (C - A) (C + A) = 0 Concept: Concept of Identity.