Question

2 х/5 + 1 = у/2
2х/5 + у = -2

3 х+2 у=10
5 х+3 у=12

Answer 1

$left { { frac{2x}{5}+1 = frac{y}{2} } atop { frac{2x}{5}+y=-2 }} right. \\ 1-y= frac{y}{2}+2 |cdot(-2)\\ 2y+y=-2\\ 3y=-2\\ y=- frac{2}{3}\\\ frac{2x}{5}- frac{2}{3}=-2\\ frac{2x}{5}=-2+ frac{2}{3} | cdot15 \\ 6x=-30+10\\ 6x=-20\\ x=- frac{10}{3}$

Ответ: $(- frac{10}{3}; - frac{2}{3})$


$left { {{3x+2y=10 |cdot3} atop {5x+3y=12} |cdot2} right. \\\ left { {9x+6y=30} atop {10x+6y=24}} right.\\ -x=6\ x=-6\\ 3cdot(-6)+2y=10\ -18+2y=10\ 2y=28\ y=14$

Ответ: $(-6;14)$