Question

a+b=12 si ab=24
Calculati 1 supra a + 1 supra b

Answer 1

1/z+1/b aducem la acelasi numitor si obtinem: b/ab+a/ab=(a+b)/ab inlocuim  cu
a+b=12 si ab=24 obtinem (a+b)/ab=12/24=1/2

Answer 2

a + b = 12
a * b = 24

$\frac{1}{a}+ \frac{1}{b}=\frac{b}{ab}+ \frac{a}{ab} = \frac{a+b}{ab}=\frac{12}{24}= \frac{1}{2}$