Question

Жизненно!!

Розв’яжіть систему рівнянь:

{ 5x + 3y = 7,
{ - 2x + 4 y = - 8.

Answer 1

Рішення тут тут тут тут тут

Answer 2

$\displaystyle\bf\\\left \{ {{5x+3y=7} \atop {-2x+4y=-8 \ |:(-2)}} \right. \\\\\\\left \{ {{5x+3y=7} \atop {x-2y=4 }} \right.\\\\\\\left \{ {{x=2y+4} \atop {5\cdot(2y+4)+3y=7}} \right.\\\\\\\left \{ {{x=2y+4} \atop {10y+20+3y=7}} \right. \\\\\\\left \{ {{x=2y+4} \atop {13y=-13}} \right. \\\\\\\left \{ {{x=2\cdot(-1)+4} \atop {y=-1}} \right. \\\\\\\left \{ {{x=2} \atop {y=-1}} \right. \\\\\\Otvet \ : \ (2 \ ; \ -1)$