Question

ДАЮ 100 БАЛОВ ПОМОГИТЕ ПЖ

Answer 1

$\displaystyle\bf\\1)\\\\\left \{ {{3x+2y=1 \ |\cdot5} \atop {2x+5y=8 \ |\cdot(-2)}} \right. \\\\\\+\left \{ {{15x+10y=5} \atop {-4x-10y=-16}} \right. \\-----------\\11x=-11\\\\x=-1\\\\2y=1-3x=1-3\cdot(-1)=1+3=4\\\\y=4:2=2\\\\Otvet \ : \ (-1 \ ; \ 2)$

$\displaystyle\bf\\2)\\\\\left \{ {{3x-2y=12 \ |\cdot3} \atop {4x+3y=-1 \ |\cdot2}} \right. \\\\\\+\left \{ {{9x-6y=36} \atop {8x+6y=-2}} \right. \\-----------\\17x=-34\\\\x=2\\\\2y=3x-12=3\cdot 2-12=6-12=-6\\\\y=-6:2=-3\\\\Otvet \ : \ (2 \ ; \ -3)$

$\displaystyle\bf\\3)\\\\\left \{ {{3x-2y=0 \ |\cdot3} \atop {5x-3y=19 \ |\cdot(-2)}} \right. \\\\\\+\left \{ {{9x-6y=0} \atop {-10x+6y=-38}} \right. \\-----------\\-x=-38\\\\x=38\\\\2y=3x=3\cdot38=114\\\\y=114:2=57\\\\Otvet \ : \ (38 \ ; \ 57)$