Question

factorise (m+n)^2-(m-n)^2​

Answer 1

Answer:

m²+2mn+n²-(m²-2mn+n²)

m²+2mn+n²-m²+2mn-n²

2mn+2mn

4mn

Answer 2

Given: A polynomial expression (m+n)² - (m-n)²

To find: Factorisation of the expression

Solution: (m+n)² should follow the rules of (a+b)², where

(a+b)² = a² + 2ab + b².

Similarly, (m-n)² should follow the rules of (a-b)², where

(a-b)² = a² - 2ab + b².

Therefore, putting the values

(m+n)² - (m-n)²

= m² + 2mn + n² - (m² - 2mn + n²)

= m² + 2mn + n² - m² + 2mn - n²

= 2mn + 2mn

= 4mn

Answer: (m+n)² - (m-n)² = 4mn