Question

Помогите, пожалуйста, решить систему.

Answer 1

$left { {{y=(12-6z)/2} atop {2z^2-(3*(12-6z))/2=-7}} right.$$left { {{y=(12-6z)/2} atop {4z^2+18z-22=0}} right.$$left { {{y=(12-6z)/2} atop {z1=-5.5}} right.$$left { {{y=(12-6z)/2} atop {z2=1}} right.$$left { {{6z+2y=12} atop {2z^2-3y= -7}} right.$
решаем квадратное уравнение
$4z^2+18z-22=0$
D=324+352=676
z1=(-18-26)/8= -5.5
z2=(-18+26)/8=1
$left { {{z1= -5.5} atop {y1=(12-6*(-5.5))/2=22.5}} right.$$left { {{z2=1} atop {y2=(12-6*1)/2=3}} right.$