Question

seja M= a² + b-² e N = a-²+ b². para a = 2 e b = -2, o valor de m + n é

Answer 1

para a = 2 e b = -2

M= a² + b-² = 2² + (-2)-² = 4 + 1/4 = (16+1)/4 = 17/4

N = a-²+ b² = 2-²+ (-2)² = 1/4 + 4 = = (1+16)/4 = 17/4

M+N= 17/4+17/4=34/4(:2)=17/2

Answer 2

$m = {a}^{2} + {b}^{ - 2} = {a}^{2} + \frac{1}{ {b}^{2} } = {2}^{2} + \frac{1}{ {( - 2)}^{2} } = 4 + \frac{1}{4} = \frac{16 + 1}{4} = \frac{17 }{4}$
$n = {a}^{ - 2} + {b}^{2} = \frac{1}{{a}^{2} } + {b}^{2} = \frac{1}{ {2}^{2} } + {( - 2)}^{2} = \frac{1}{4} + 4 = \frac{1 + 16}{4} = \frac{17}{4}$
$m + n = \frac{17}{4} + \frac{17}{4} = 2 \times \frac{17}{4} = \frac{17}{2}$