已知A=x^2-xy-y^2,B=3xy+x^2.x,y满足条件(x-3)^2+(y+2)^2=0求1/2[2(A-B)-3A+1_数学解答

已知A=x^2-xy-y^2,B=3xy+x^2.x,y满足条件(x-3)^2+(y+2)^2=0求1/2[2(A-B)-3A+1/3[3（A+2B）-3A]-1/2A
完整

人气：416 ℃　时间：2020-04-13 05:20:15

解答

(x-3)^2+(y+2)^2=0(x-3)^2=0,(y+2)^2=0x=3y=-21/2[2(A-B)-3A+1/3[3（A+2B）-3A]-1/2A=1/2[(A-B)-3A+A+2B-3A]-1/2A=1/2[A-B-3A+A+2B-3A]-1/2A=1/2[A-3A+A-3A-B+2B]-1/2A=1/2[-4a+B]-1/2A=-2A+1/2B-1/2A=-5/2A+1/2B=-5...