Question

решите систему уравнения 3х + 5у=16 и 2х+3у=9

Answer 1

$\displaystyle \left \{ {{3x+5y=16\; \; |\cdot 2} \atop {2x+3y=9\; \; |\cdot 3\; }} \right. \\\\-\left \{ {{6x+10y=32} \atop {6x+9y=27}} \right. \\\\\left \{ {{6x+10y-6x-9y=32-27} \atop {x=\dfrac{9-3y}2 \qquad \qquad \qquad \qquad}} \right. \\\\\left \{ {{y=5\qquad \qquad \qquad } \atop {x=\dfrac{9-3\cdot 5}2 =-3}} \right.$

Ответ: (-3;5).