Question

Encontre o valor de y em:
$12 {}^{2} + y {}^{2} = 9 {}^{2} + (3 + y) {}^{2}$
Com cálculo.​

Answer 1

Explicação passo-a-passo:

12² + y² = 9² + (3 + y)²

12.12 + y² = 9.9 + 3.3 + 3.y + 3.y + y.y

144 + y² = 81 + 9 + 6y + y²

144 + y² = 90 + 6y + y²

y² - y² - 6y = 90 - 144

- 6y = - 54 .(-1)

6y = 54

y = 54/6

y = 9

Answer 2

Oie, Td Bom?!

$12 {}^{2} + y {}^{2} = 9 {}^{2} + (3 + y) {}^{2}$

$12 {}^{2} + y {}^{2} = 9 {}^{2} + 9 + 6y + y {}^{2}$

$12 {}^{2} = 81 + 9 + 6y$

$144 = 90 + 6y$

$- 6y = 90 - 144$

$- 6y = - 54$

$y = \frac{ - 54}{ - 6}$

$y = \frac{54}{6}$

$y = 9$

Att. Makaveli1996