已知m2-mn=21,mn-n2=15求m2-2mn+n2的值
已知m2-mn=21,mn-n2=15求m2-2mn+n2的值
数学人气:340 ℃时间:2019-11-06 23:55:01
优质解答
∵m^2-mn=21、mn-n^2=15,∴两式相减,得:m^2-2mn+n^2=21-15=6.
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