当a+b=5,x-y=2时,代数式a^2+2ab+b^2-x+y的值等于
问题描述:
当a+b=5,x-y=2时,代数式a^2+2ab+b^2-x+y的值等于
答
a²+2ab+b²-x+y
=(a+b)²-(x-y)
=5²-2
=25-2
=23