Question

without expanding prove that

Answer 1

using completing square method

Answer 2

Answer:

Solution:

= (x + y)(x - y) + (y + z)(z - y) + (z + x)(z - x)

= x² - y² + y² - z² + z² - x² ------------------------- (∵ a² - b² = (a + b)(a - b))            

= 0      

Step-by-step explanation: