Question

急 2x∧2-4x-2.5=0 -y∧2+2y+3=0 （x-1）∧2-2（x-1）-3=0

Answer 1

1) 2x^2-4x-2.5=0

x^2-2x-5/4=0,

(x-1)^2=9/4,

x-1=土3/2,

x1=5/2,x2=-1/2.

2)-y^2+2y+3=0,

y^2-2y-3=0,

(y-3)(y+1)=0,

y1=3,y2=-1.

3)（x-1）^2-2（x-1）-3=0,

由2)得x-1=3,或x-1=-1,

∴x1=4,x2=0.