<span>y^2+5y - 14 = 0
y1+y2=-5
y1*y2=-14
y1=-7 y2=2
z^2 - 2z - 15 = 0
z1+z2=2
z1*z2=-15
z1=-3 z2=5
c^2 + 2c - 8 =0
c1+c2=2
c1*c2=-8
c1=-2 c2=4
t^2 + 9t - 10 = 0
t1+t2=9
t1*t2=-10
t1=510 t2=-1</span>
Y=x²-2, y=-x
-x=x²-2, x²+x-2=0, (x+2)(x-1)=0
a)x+2=0, x=-2, y=-(-2)=2 , /x,y/=/-2,2/
b)x-1=0, x=1, y=-1, /x,y/=/1,-1/