Question

Factorize m(m-1) - n(n-1)

Answer 1

m(m-1)-n(n-1)
m²-m-n²+n
(m²-n²)-1(m-n)
(m-n)(m+n)-1(m-n)
taking (m-n) common
(m-n)(m+n-1)
hope this helps

Answer 2

We needs a formula which is

a² - b² = ( a+ b ) ( a - b )

now

m ( m - 1 ) - n ( n - 1 )

= m² - m - n² + n

= m² - n² - 1 ( m - n )

= ( m + n ) ( m - n ) - 1 ( m - n )

= ( m - n ) { ( m + n - 1 ) }

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