Question

1. Calcule os produtos:

a) (x + 5).( x + 2)
b) ( 3x + 2) ( 2x + 1)
c) ( x + 7). (x-4)
d) (3x +4).(2x - 1)
e) ( x - 4y). (x-y)
f) ( 5x – 2). ( 2x - 1)
g) ( 3x + 1) . (3x - 1)
h) (2x + 5). ( 2x_5)​

Answer 1

a)

$(x + 5) \times (x + 2) \\ {x}^{2} + 2x + 5x + 10 \\ {x}^{2} + 7x + 10$

b)

$(3x + 2) \times (2x + 1) \\ 6 {x}^{2} + 3x + 4x + 2 \\ {6}^{2} + 7x + 2$

c)

$(x + 7) \times (x - 4) \\ {x}^{2} - 4x + 7x - 28 \\ {x}^{2} + 3x - 28$

d)

$(3x + 4) \times (2x - 1) \\ 6 {x}^{2} - 3x + 8x - 4 \\ {6}^{2} + 5x - 4$

e)

$(x - 4y) \times (x - y) \\ {x}^{2} - xy - 4xy + {4y}^{2} \\ {x}^{2} + {4y}^{2} - 5xy$

f)

$(5x - 2) \times (2x - 1) \\ 10 {x}^{2} - 5x - 4x + 2 \\ 10 {x}^{2} - 9x + 2$

g)

$(3x + 1) \times (3x - 1) \\ 6 {x}^{2} - 3x + 3x - 1 \\ 6 {x}^{2} - 1$

h)

$(2x + 5) \times (2x - 5) \\ 4 {x}^{2} - 25$