(a²+2ab+b²)÷(a+b)= (4A²-9b²)÷(2A+3B)=若X+Y=5,xy=3 则X²Y+XY= X²Y+2X²Y平方+XY
问题描述:
(a²+2ab+b²)÷(a+b)= (4A²-9b²)÷(2A+3B)=
若X+Y=5,xy=3 则X²Y+XY= X²Y+2X²Y平方+XY
答
1.(a+b)^2/(a+b)=a+b
2.(2A+3B)*(2A-3B)/(2A+3B)=2A-3B
3.根据题目求得x=(5+-根号13)/2,y=(5-+根号13)/2,然后求得结果,第4问也一样,结果自己算下吧,太难打了...