Question

Pls answer these questions pls

Answer 1

Answer:

12. answer

(x-y) (x+y) + (y-z) (y+z) + (z-x) (z+x)=0

using formula of (a-b)(a+b)=a²-b²

x²-y² + y²-z² + z²-x²

cut the value of ➕ and ➖

0=0

hence proved.

13.(2x+3)²

by using formula of (a+b)²=a²+b²+2ab

(2x)² + (3)² + 2 × 2x ×3

4x² + 9 + 12x. ans.

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