集合A ={x |x²;–4=0}與集合B =x ||x |=2}的關係是

集合A ={x |x²;–4=0}與集合B =x ||x |=2}的關係是


A=B



(x-5)²;-2(x-5)=0


原式變為
(x-5)(x-5-2)=0(選取公因式x-5)
(x-5)(x-7)=0
x1=5
x2=7
請採納



(x²;+y²;)²;—3(x²;+y²;)—4=0求x²;+y²;=_______


4



1.(x²;+y²;)²;-4(x²;+y²;)-5=0,則x²;+y²;=()
2.若x²;-3xy-4y²;=0,則x/y=()
3.3x²;+2x=3,


解(x²;+y²;)²;-4(x²;+y²;)-5=0[(x²;+y²;)-5][(x²;+y²;)+1]=0∴x²;+y²;=5或x²;+y²;=-1(舍去)∴x²;+y²;=5x²;-3xy-4y²;=0(x-4y)(x +y)=0∴x=4y或x…