4 −Write 4 in the under rooted form
= ( 2 )² − ( 2a + 3b )²
Factorise as the difference of 2 squares = a² − b² = ( a + b )( a − b )
= [ 2 + ( 2a + 3b ) ][ 2 − ( 2a + 3b ) ]
= ( 2 + 2a + 3b )( 2 - 2a - 3b )
Arrange
= ( 2a + 3b + 2 )( 2 − 2a − 3b ) ( 2a + 3b )² YOUR WELCOME
