Question

calcule os produtos...


1) (3x + 4) (2x - 1)
2) (x - 4y) (x - y)
3) (5x - 2) (2x - 1)
4) (3x + 1) (3x - 1)
5) (2x + 5) (2x -5)
6) (x - 1) ( x - 2) ( x - 3)

Answer 1

1)
= (3x + 4).(2x - 1)
= 6x² - 3x + 8x - 4
= 6x² + 5x - 4

2)
= (x - 4y).(x - y)
= x² - xy - 4xy + 4y²
= x² - 5xy + 4y²

3)
= (5x - 2).(2x - 1)
= 10x² - 5x - 4x + 2
= 10x² - 9x + 2

4)
(3x + 1).(3x - 1) = 9x² - 3x + 3x - 1 = 9x² - 1

5)
(2x + 5).(2x - 5) = 4x² - 5.2x + 5.2x - 25 = 4x² - 25

6)
= (x - 1).( x - 2).( x - 3)

= (x² - 2x - x + 2).(x - 3)
= (x² - 3x + 2).(x - 3)
= x².x + x².(-3) - 3x.x - 3x.(-3) + 2.x + 2.( - 3)
= x³ - 3x² - 3x² + 9x + 2x - 6
= x³ - 6x² + 11x - 6

Answer 2

1)

= (3x + 4).(2x - 1)

= 6x² - 3x + 8x - 4

= 6x² + 5x - 4

2)

= (x - 4y).(x - y)

= x² - xy - 4xy + 4y²

= x² - 5xy + 4y²

3)

= (5x - 2).(2x - 1)

= 10x² - 5x - 4x + 2

= 10x² - 9x + 2

4)

(3x + 1).(3x - 1) = 9x² - 3x + 3x - 1 = 9x² - 1

5)

(2x + 5).(2x - 5) = 4x² - 5.2x + 5.2x - 25 = 4x² - 25

6)

= (x - 1).( x - 2).( x - 3)

= (x² - 2x - x + 2).(x - 3)

= (x² - 3x + 2).(x - 3)

= x².x + x².(-3) - 3x.x - 3x.(-3) + 2.x + 2.( - 3)

= x³ - 3x² - 3x² + 9x + 2x - 6

= x³ - 6x² + 11x - 6