Question

Rezolvati sistemele: PUNCTUL A rapid va rog

Answer 1

Răspuns:

$\frac{3}{x}+\frac{7}{y} =2\\\frac{6}{x} -\frac{21}{y}=-1\\ Fie \frac{1}{x}= a; \frac{1}{y}=b => \\3a+7b=2 |*(-2) \\6a-21b=-1\\\\=> -6a-14b=-4\\6a-21b=-1\\=>\\-35b=-5 => b = \frac{1}{7}\\=> -6a-2=-4 => -6a= -2 => a = \frac{1}{3}$

$\frac{1}{x}=\frac{1}{3}=> x = 3\\\\\\\frac{1}{y} =\frac{1}{7} => y = 7$

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