数学先化简再求值!
来源:学生学帮网 编辑:学帮网 时间:2024/06/16 21:06:06
数学先化简再求值!
原式=y(x+2y)(x-2y)/(x+2y)²*(4xy+x²-2xy)/(x-2y)
=y(x-2y)/(x+2y)*(x²+2xy)/(x-2y)
=y(x-2y)/(x+2y)*x(x+2y)/(x-2y)
=xy
=(√2-1)(√2+1)
=2-1
=1
数学先化简再求值!
原式=y(x+2y)(x-2y)/(x+2y)²*(4xy+x²-2xy)/(x-2y)
=y(x-2y)/(x+2y)*(x²+2xy)/(x-2y)
=y(x-2y)/(x+2y)*x(x+2y)/(x-2y)
=xy
=(√2-1)(√2+1)
=2-1
=1