Question

2)Calcule: a) ( x + y) (x – y)= b) (x + 7) ( x - 7)= c) ( 2a + 5) ( 2a – 5)= d) (3x + 2 ) ( 3x - 2) Alguém poderia me ajudar...e agente... obrigada

Answer 1

Explicação passo-a-passo:

a)

$\sf (x+y)\cdot(x-y)=x^2-y^2$

b)

$\sf (x+7)\cdot(x-7)=x^2-7^2$

$\sf (x+7)\cdot(x-7)=x^2-49$

c)

$\sf (2a+5)\cdot(2a-5)=(2a)^2-5^2$

$\sf (2a+5)\cdot(2a-5)=4a^2-25$

d)

$\sf (3x+2)\cdot(3x-2)=(3x)^2-2^2$

$\sf (3x+2)\cdot(3x-2)=9x^2-4$

Answer 2

Oie, Td Bom?!

a)

$= (x + y) \: . \: (x - y) \\ = x {}^{2} - y {}^{2}$

b)

$= (x + 7) \: . \: (x - 7) \\ = x {}^{2} - 7 {}^{2} \\ = x {}^{2} - 49$

c)

$= (2a + 5) \: . \: (2a - 5) \\ = (2a) {}^{2} - 5 {}^{2} \\ = 4a {}^{2} - 25$

d)

$= (3x + 2) \: . \: (3x - 2) \\ = (3x) {}^{2} - 2 {}^{2} \\ = 9x {}^{2} - 4$

Att. Makaveli1996