17x+13y=40

13x+17y=50

система уравнений!

X = (40-13y) / 17 13 (40-13y) / 17+17y=50|*17 520-169y+289y=850 120y=850-520 120y=330|:120 y=2,75 x = (40-13*2,75) / 17 = (40-35,75) / 17=4,25/17 x=0,25 17*0,25+13*2,75=40 4,25+35,75=40 40=40-истина. 13*0,25+17*2,75=50 3,25+46,75=50 50=50-истина.