Question

ayudaaaa pooorfavorrr ​

Answer 1

Muchos signos los cambié porque no se pueden poner aquí

8)

Recuerda:

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

...

$a \: b = \frac{ {a}^{2} - {b}^{2} }{a + b} \\ a \: b = \frac{(a + b)(a - b)}{a + b} \\ a \: b \: = a - b$...

$= (5 \: 2) + (7 \: 4) \\ = (5 - 2) + (7 - 4) \\ = 3 + 3 \\ = 6$

9)

$|Q| = {Q}^{2} + 2Q \\ |Q| =Q( Q + 2)$

a)

$|1| = 1(1 + 2) \\ |1| = 3$

b)

$| |1| | = |3| \\ | |1| | = 3(3 + 2) \\ | |1| | = 15$

c)

$|2| = 2(2 + 2) \\ |2| = 8$

d)

$| |1| | + |2| = 15 + 8 \\ | |1| | + |2| = 23$

10)

$= (\binom{3 \times 4 - 5 \times 2}{9 \times 3 - 8 \times 3} \binom{7 \times 2 - 6 \times 2}{5} ) \\ = \binom{ 2}{3} \binom{2}{5} \\ = 2 \times 5 - 3 \times 2 \\ = 4$