3x^2+2y^2=77 |*3
9x^2+6y^2=77x
9x^2+6y^2=231
9x^2+6y^2=77x
231-77x=0
-77x=-231
x=3
3*(3)^2+2y^2=77
27+2y^2=77
2y^2=77-27
2y^2=50
y^2=50\2
y^2=25
y=5
Ответ:(3;5)
-5х+9(-1+2х)=9х-1
-5х-9+18х-9х=-1
4х=-1+9
4х=8
х=2
<em><u>Ответ: 2.</u></em>
3х²-3х+2х-2+х²+9=40х+40
4х²-х+7=40х+40
4х²-х-40х+7-40=0
4х²-41х-33=0
D = 1681 - 4 * 4 * (-33) = 2209