Question

a,b nr reale
a+b=2 radical din 2
a x b=2
1/a + 1/b = ?
a x a + b x b = ?
dau coroana + 50 puncte vaaa rog rezolvare completa

Answer 1

$\frac{1}{a}$+$\frac{1}{b}$=$\frac{a+b}{ab}$=$\frac{2 \sqrt{2} }{2}$=$\sqrt{2}$
stim ca a+b=2√2 ridicam la patrat
(a+b)²=(2√2)²
a²+2ab+b²=8
a²+b²=8-2ab
a²+b²=8-2·2
a²+b²=4
a·a+b·b=a²+b²=4