Question

Resolva as seguintes multiplicações
(3-ab)(3+ab)
(xy-3z)(xy+3z)
(x²+1)(x²-1)
(y²-3z)(y²+3z)

Answer 1

Oie, Td Bom?!

1.

$= (3 - ab) \: . \: (3 + ab)$

$= 3 {}^{2} - (ab) {}^{2}$

$= 9 - a {}^{2} b {}^{2}$

2.

$= (xy - 3z) \: . \: (xy + 3z)$

$= (xy) {}^{2} - (3z) {}^{2}$

$= x {}^{2} y {}^{2} - 9z {}^{2}$

3.

$= (x {}^{2} + 1) \: .\: (x {}^{2} - 1)$

$= (x {}^{2} ) {}^{2} - 1 {}^{2}$

$= x {}^{4} - 1$

4.

$= (y {}^{2} - 3z) \: . \: (y {}^{2} + 3z)$

$= (y {}^{2} ) {}^{2} - (3z) {}^{2}$

$= y {}^{4} - 9z {}^{2}$

Att. Makaveli1996