Систему уравнений 1) х-у=6(х+у) х∧2-у∧2=6 2)х∧2+ху=2 у-3х=7 3)х+у∧2=2 2у∧+х∧2=3

1) х - у = 6 * (х + у); х - у = 6 * х + 6 * у; х = (-7 * у)/5;

(-7 * у)^2/5^2 - у^2 = 6;

49 * у^2 - 25 * у^2 = 25 * 6;

24 * у^2 = 150;

у^2 = 150/24 = 6,25;

у1 = 2,5; у2 = -2,5.

х1 = (-7 * 2,5)/5 = -3,5;

х2 = (-7 * (-2,5))/5 = 3,5;

2) у = 7 + 3 * х;

х^2 + х * (7 + 3 * х) = 2;

х^2 + х * 7 + 3 * х^2 = 2;

4 * х^2 + х * 7 - 2 = 0;

D = 49 + 32 = 81;

х1 = (-7 + 9)/8 = 1/4; у1 = 7 + 3/4 = 31/4;

х2 = (-7 - 9)/8 = -2; у2 = 7 - 3 * 2 = 1;

3) х = 2 - у^2;

у^2 + (2 - у^2)^2 = 3;

у^2 + 4 - 4 * у^2 + у^4 = 3;

у^4 - 3 * у^2 + 1 = 0;

t = у^2; t^2 - 3 * t + 1 = 0;

D = 9 - 4 = 5;

t1 = (3 + 2,24)/2 = 2,62; у1 = 1,62; у2 = -1,62; х1 = 2 - 2,62 = 0,62;

t2 = (3 - 2,24)/2 = 0,38; у3 = 0,6; у4 = -0,6; х2 = 2 - 0,38 = 1,62.