已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值 解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64a方+b方=34,(a-b)方=a方-2ab+b方=34-2*

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已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值 解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64a方+b方=34,(a-b)方=a方-2ab+b方=34-2*
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已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值 解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64a方+b方=34,(a-b)方=a方-2ab+b方=34-2*
已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值 解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64
已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值
解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64
a方+b方=34,(a-b)方=a方-2ab+b方=34-2*15=4
a>b 所以a-b=√4=2
已知实数x+1/x=4,且x>1/x,试求x-1/x的值

已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值 解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64已知实数a,b满足a+b=8,ab=15,且a>b,试求a-b的值解a+b=8,ab=15 (a+b)平方=a方+2ab+b方=64a方+b方=34,(a-b)方=a方-2ab+b方=34-2*
x+1/x=4
(x+1/x)^2=4^2
x^2+1/x^2+2=16
x^2+1/x^2=14
x^2+1/x^2-2=(x-1/x)^2=12
x-1/x=√12=2√3