若3X+2Y=0(XY≠0)则代数式2X+3Y/2X-3Y=若3X+2Y=0,则代数式2X+3Y/2X-3Y=?(XY不等于0)
问题描述:
若3X+2Y=0(XY≠0)则代数式2X+3Y/2X-3Y=
若3X+2Y=0,则代数式2X+3Y/2X-3Y=?(XY不等于0)
答
5/13
答
Y=-3X/2
13X/2-9/4 或 -3Y-9/4
答
若3X+2Y=0,则代数式2X+3Y/2X-3Y=?(XY不等于0) ---------------------------------------------用换元法计算,简单,不容易错3x+2y=03x=-2y可以设3x=-2y=6k那么x=2k,y=-3k代入2X+3Y/2X-3Y,有2X+3Y/2X-3Y=(4k-9k)/(4k+9k...
答
3X+2Y=0 所以x=-2y/3 带入 2x=-4y/3 为
(-4y/3+3y)/(-4y/3-3y)=(5y/3)/(-13y/3)=-5/13