1:x²+2xy+y²=(x+y)²=(2√3)²=122:x²-y² =(x+y)(x-y)=2√3*2=4√3
1=>(X+Y)2=122=>(X+Y)(X-Y)=4根号3
(1)x²+2xy+y²=(x+y)²=12(2)x²-y² =(x+y)*(x-y)=4√3
(1) (x+y)*(x+y)=12(2)(x-y)*(x+y)=4√3
