Question

пж помогите даю всьо шо є 50Б

і розпишіть пж​

Answer 1

$1)\\+\left \{ {{3x-8y=18} \atop {-3x+4y=-6}} \right.\\-------\\ -4y=12\\\\y=-3\\\\3x=4y+6=4*(-3)+6=-12+6=-6\\\\x=-6:3=-2\\\\Otvet:\boxed{(-2 \ ; \ -3)}\\\\\\2)\\+\left \{ {{2x+5y=6} \atop {8x-5y=-1}} \right.\\-------\\ 10x=5\\\\x=0,5\\\\5y=6-2x=6-2*0,5=6-1=5\\\\y=5:5=1\\\\Otvet:\boxed{(0,5 \ ; \ 1)}$

$3)\\\left \{ {{4x+5y=6} \atop {4x+3y=2}|*(-1)} \right. \\\\+\left \{ {{4x+5y=6} \atop {-4x-3y=-2}} \right.\\ -------\\2y=4\\\\y=2\\\\4x=2-3y=2-3*2=2-6=-4\\\\x=-4:4=-1\\\\Otvet:\boxed{(-1 \ ; \ 2)}\\\\\\4)\\\left \{ {{2x+3y=8} \atop {x-y=-1}|*3} \right.\\\\+\left \{ {{2x+3y=8} \atop {3x-3y=-3}} \right.\\ ------\\5x=5\\\\x=1\\\\y=x+1=1+1=2\\\\Otvet:\boxed{(1 \ ; \ 2)}$