Question

Решите пж за 20 балов

Answer 1

Объяснение:

№1.

а)

$\displaystyle\\\left \{ {{\frac{x}{2}-\frac{y}{3}=0\ |*6 } \atop {2x-y=2}} \right.\ \ \ \ \ \ \left \{ {{3x-2y=0} \atop {y=2x-2}} \right. \ \ \ \ \ \ \left \{ {{3x-2*(2x-2)=0} \atop {y=2x-2}} \right. \\\\\\\left \{ {{3x-4x+4=0} \atop {y=2x-2}} \right. \ \ \ \ \ \ \left \{ {{-x=-4\ |*(-1)} \atop {y=2x-2}} \right.\ \ \ \ \ \ \left \{ {{x=4} \atop {y=2*4-2}} \right. \ \ \ \ \ \ \left \{ {{x=4} \atop {y=6}} \right. .$

Ответ: (4;6).

б)

$\displaystyle\\\left \{ {\frac{x-5}{3} =\frac{3y+2}{4}\ |*12 } \atop {4x+9y=-10}} \right.\ \ \ \ \ \ \left \{ {{4*(x-5)=3*(3y+2)} \atop {4x+9y=-10}} \right. \ \ \ \ \ \ \left \{ {{4x-20=9y+6} \atop {4x+9y=-10}} \right. \\\\\\+\left \{ {{4x-9y=26} \atop {4x+9y=-10}} \right. \\\\8x=16\ |:8\\\\x=2.\\\\4*2+9y=-10\\\\8+9y=-10\\\\9y=-18\ |:9\\\\y=-2.$

Ответ: (2;-2).