Question

 2) a) Show that : (a + b) (a - b) + (b - c) (b + c) + (c -a) (c + a) = 0​

Answer 1

Answer:

$we \: knw \: that \: \\ (a - b)(a + b) = a {}^{2} - b {}^{2}$

so,

Here,

$a {}^{2} - b {}^{2} + b {}^{2} - c {}^{2} + c {}^{2} - a {}^{2} = a {}^{2} - a{}^{2} + b {}^{2} - b {}^{2} + c {}^{2} - c {}^{2} = 0$

all the positive nax negative terms will cancle out and we get zero as the answer

=0