Question

factorise this sum............

Answer 1

$\textbf{\underline{Question :}}$ Factorise 9x² - 25y² - 3x + 5y.

$\Longrightarrow{\boxed{\bold{Answer : ( 3x - 5y )( 3x + 5y - 1 )}}}$

$\textbf{Step by step explanation :}$

= 9x² - 25y² - 3x + 5y

= (3x)² - (5y)² - 3x + 5y

$\bold{Since\:a^2 - b^2 = ( a + b )( a - b )}$

= ( 3x + 5y )( 3x - 5y ) - 3x + 5y

$\textsf{Taking '-' common out,}$

= ( 3x + 5y )( 3x - 5y ) - ( 3x - 5y )

$\textsf{Now taking ( 3x - 5y ) common,}$

= ( 3x - 5y )[ ( 3x + 5y ) - 1 ]

$\textbf{\textit{= ( 3x - 5y )( 3x + 5y - 1 )}}$