Решите систему уравнений [tex] \left \{ {{ \frac{2}{x}+ \frac{1}{y}=4 } \atop { \frac{1}{x}- \frac{3}{y}=9 }} ight. [/tex]

1/x=a,1/y=b{2a+b=4/*3⇒6a+3b=12{a-3b=9прибавим7a=21a=21:7a=3⇒1/x=3⇒x=1/36+b=4b=4-6b=-2⇒1/y=-2⇒y=-1/2(1/3;-1/2)