Question

Calcule os produtos abaixo: a) (x+5).(x+2) b) (3x+2).(2x2+1) c) (3x+4).(2x-1) d) (6x2-4).(6x2+4)e) (3x2-4x-3).(x+1) f) (x-1).(x-2).(-3) g) (x3-2).(x3+8) h) (x2+2).(x2+6)

Answer 1

a) (x+5)(x+2) =

x (x+2) + 5 (x+2) =

x² + 2x + 5x + 10 =

x² + 7x + 10

b) (3x + 2)(2x² + 1) =

3x (2x² + 1) + 2 (2x² + 1) =

6 x³ + 3x + 4x² + 2 =

6x³ + 4x² + 3x + 2

c) (3x + 4) (2x - 1) =

3x (2x -1) + 4 (2x -1) =

6x² - 3x +8 x - 4 =

6x² +5x - 4

d) (6x² -4) (6x² + 4) =

(6x²)² - 4² =

36 x⁴ - 16 =

4(9x⁴ - 4)

e) (3x² - 4x -3 ) (x+ 1) =

x (3x² - 4x -3) + 1 (3x² -4x -3) =

3x³ - 4x² - 3x + 3x² - 4x - 3 =

3x³ - x² - 7x - 3

f) (x-1) (x-2) =

x (x-2) -1 (x-2) =

x² -2x -x + 2 =

x² - 3x + 2

g) (x³ -2) (x³ + 8) =

x³ (x³ +8) -2 (x³ +8) =

x⁶ + 8x³ - 2x³ - 16 =

x⁶ + 6x³ - 16

h) (x² + 2) (x² + 6) =

x² (x² +6) + 2 (x² + 6) =

x⁴ + 6x² + 2x² + 12 =

x⁴ + 8x² + 12