Question

3)Calcule os quadrados da soma: a) (2a + 5)² b) (a + 2b)² c) (5a + 3b)²

Answer 1

Oie, Td Bom?!

• Usando $(x + y) {}^{2} = x {}^{2} + 2xy + y {}^{2}$, desenvolva as expressões.

a)

$= (2a + 5) {}^{2} \\ = (2a) {}^{2} + 2 \: . \: 2a \: . \: 5 + 5 {}^{2} \\ = 4a {}^{2} + 20a + 25$

b)

$= (a + 2b) {}^{2} \\ = a {}^{2} + 2a \: . \: 2b + (2b) {}^{2} \\ = a {}^{2} + 4ab + 4b {}^{2}$

c)

$= (5a + 3b) {}^{2} \\ = (5a) {}^{2} + 2 \: . \: 5a \: . \: 3b + (3b) {}^{2} \\ = 25a {}^{2} + 30ab + 9b {}^{2}$

Att. Makaveli1996