Question

1) Resolva os seguintes produtos use a distributiva: a) (x+2). (x-4) = b) (2x-4). (8x-9) = c) (14y-5). (12y-8) =

Answer 1

a) ( X + 2 ) × ( X - 4 )

= X × ( X - 4 ) + 2 × ( X - 4 )

= X² - 4x + 2 × ( X - 4 )

= x² - 4x + 2x - 8

= x² - 2x - 8

b) ( 2x - 4 ) × ( 8x - 9 )

= 2x × ( 8x - 9 ) - 4 × ( 8x - 9 )

= 16x² - 18x - 4 × ( 8x - 9 )

= 16x² - 18x - 32x + 36

= 16x² - 50x + 36

c) ( 14y - 5 ) × ( 12y - 8 )

= 14y × ( 12y - 8 ) - 5 × ( 12y - 8 )

= 168y² - 112y - 5 × ( 12y - 8 )

= 168y² - 112y - 60y + 40

= 168y² - 172y + 40