先化简再求值:(根号a+根号b)的平方-(根号a-根号b)的平方,其中a=2,b=8
求解 大虾 速度些!
人气:166 ℃ 时间:2019-10-17 04:31:12
解答
原式=a+b+2倍根号ab-a-b+2倍根号ab
=4倍根号ab带入a,b的值=4倍根号16根号16=4或者=-4
所以4倍根号16=16或者=-16
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