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)
Sin180*cos a-cos180*sin a+cos 90*cos a-sin90*sina=
=0*cos a-(-1)*sin a+0*cos a-1*sina=sina-sina=0
-3х+4=-5+2х+12
-3х+4=7+2х
х=3
X+3+x-2+2√(x+3)(x-2)>2x+4
2x+1+2√(x^2-6+x)>2x+4
4(x^2+x-6)>9
4x^2-24+4x>9
4x^2+4x-33>0
ОДЗ x>2
4x^2+4x-33=0
x>2
x>(√34-1)/2
ответ x>(√34-1)/2