Question

х+у=680
0,8х+1,1у=580
​

Answer 1

Ответ:

х+у=680

0,8х+1,1у=580

y=680-x

0,8x+1,1×(680-x)=0,8x+748-1,1x=-0,3x+748=580

-0,3x=580-748= -168

x= -168÷(-0,3)=560

y=680-560=120