Question

розв'язати систему рівнянь способом підстановки х+2у=3 х+3у=8

Answer 1

Объяснение:

х+2у=3

х+3у=8

х=3-2у

3-2у+3у=8

у=5

х+2*5=3

х+10=3

х=-7

Answer 2

$\left \{ {{x+2y=3} \atop {x+3y=8}} \right. \\\\\left \{ {{x=3-2y} \atop {3-2y+3y=8}} \right.\\\\\left \{ {{x=3-2y} \atop {y=8-3}} \right.\\\\\left \{ {{x=3-2y} \atop {y=5}} \right.\\\\\left \{ {{x=3-2*5} \atop {y=5}} \right. \\\\\left \{ {{x=-7} \atop {y=5}} \right. \\\\Otvet:\boxed{(-7 \ ; \ 5)}$