Question

-2х+4у=1
3х-3у=2
Решительно методом сложения

Answer 1

$left { {{-2x+4y=1} atop {3x-3y=2}} right.$⇒$left { {{-2x*3+4y*3=1*3} atop {3x*2-3y*2=2*2}} right.$⇒$left { {{-6x+12y=3} atop {6x-6y=4}} right.$⇒$left { {{6y=7} atop {y= frac{7}{6} }} right.$

$6x-6y=4$
$6x-6* frac{7}{6} =4$
$6x-7=4$
$6x=4+7$
$6x=11$
$x= frac{11}{6}$

$y= frac{7}{6}$     $x= frac{11}{6}$

Проверка:
$left { {{-2* frac{11}{6} +4* frac{7}{6} =1} atop {3* frac{11}{6}-3* frac{7}{6}=2}} right.$⇒$left { {{- frac{11}{3}+ frac{14}{3} =1} atop { frac{11}{2}- frac{7}{2} =2}} right.$⇒$left { {{1=1} atop { frac{4}{2} =2}} right.$

Answer 2

умница!