Question

$(49 {l }^{2} - 100 {m}^{2} ) \div (7 l + 10m)$

Answer 1

Hi ,

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We know the algebraic identity,

a² - b² = ( a + b ) ( a - b )

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49l² - 100m²

= ( 7l )² - ( 10m )²

= ( 7l + 10m ) ( 7l - 10m ) ----( 1 )

Now ,

( 49l² - 100m² ) / ( 7l + 10m )

= ( 7l + 10m ) ( 7l - 10m ) / ( 7l + 10m )

= 7l - 10m

I hope this helps you.

:)