Question

3x+y=10 ,x*x-y=8 решить систему неравенств срочно!

Answer 1

$begin{cases}3x+y=10\x^2-y=8end{cases}Rightarrowbegin{cases}y=10-3x\x^2-10+3x=8end{cases}\x^2-10+3x=8\x^2+3x-18=0\D=9+4cdot18=81\x_{1,2}=frac{-3pm9}2\x_1=-6,;x_2=3\\begin{cases}y=28\x=-6end{cases}quadquadquadquadbegin{cases}y=1\x=3end{cases}$