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(3x+2)(x+5)+(2-3x)(x-4)

( 3 x + 2 ) ( x + 5 ) +  [ - 1 ( - 2 - 3 x ) ( x - 4 )]

( 3 x + 2 ) ( x + 5) + (  2 + 3 x ) ( x - 4 )

( 3 x + 2 ) ( x + 5  + x - 4 )

= ( 3 x + 2 ) ( 2 x + 1 )