Question

4- Calcule:
a) 2x(x+y)
b) (3x+4).(2x-1)​

Answer 1

Resposta:

a) x = -y

b) x =

Explicação passo-a-passo:

a) 2x (x + y) = 0

2x multiplica x e y, ficando:

2x^2 + 2xy = 0 ( /2 )

x*x + xy = 0 ( /x )

x + y = 0

x = -y

b) (3x+4).(2x-1)​ = 0

[3x * 2x] + [3x * (-1)] + [4 * 2x] + [4 * (-1)] => [ 6x ] + [ -3x] + [ 8x ] + [ -4 ] = 0

6x - 3x + 8x - 4 = 0

11x = 4-> x = 11/4 -> x = 2,75

Answer 2

Oie, Td Bom?!

a)

$= 2x \: . \: (x + y)$

$= 2x \: . \: x + 2xy$

$= 2x {}^{2} + 2xy$

b)

$= (3x + 4) \: . \: (2x - 1)$

$= 3x \: . \: (2x - 1) + 4(2x - 1)$

$= 6x {}^{2} - 3x + 8x - 4$

$= 6x {}^{2} + 5x - 4$

Att. Makaveli1996