阅读理解题:若x满足(210-x)(x-200)=-204,试求(210-x)²+(x-200)²的值,阅读理解题:“若x满足(210-x)(x-200)=-204,试求(210-x)²+(x-200)²的值,”设(210-x)=a,(x-200)=b,则ab
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阅读理解题:若x满足(210-x)(x-200)=-204,试求(210-x)²+(x-200)²的值,阅读理解题:“若x满足(210-x)(x-200)=-204,试求(210-x)²+(x-200)²的值,”设(210-x)=a,(x-200)=b,则ab
阅读理解题:若x满足(210-x)(x-200)=-204,试求(210-x)²+(x-200)²的值,
阅读理解题:
“若x满足(210-x)(x-200)=-204,试求(210-x)²+(x-200)²的值,”
设(210-x)=a,(x-200)=b,
则ab=-204,且a+b=(210-x)+(x-200)=10,
∵(a+b)²=a²+2ab+b²
∴a²+b²=(a+b)²-2ab=10²-2(-204)=508
即(210-x)²+(x-200)²的值为508.
同学们,根据材料,请你完成下面这一题的解答过程:
“若x满足(2013-x)²+(2011-x)²=4028,试求(2013-x)(2011-x)的值”.
阅读理解题:若x满足(210-x)(x-200)=-204,试求(210-x)²+(x-200)²的值,阅读理解题:“若x满足(210-x)(x-200)=-204,试求(210-x)²+(x-200)²的值,”设(210-x)=a,(x-200)=b,则ab
(2011-x)²=(x-2011)²
设(2013-x)=a,(x-2011)=b,
a+b=2013-x+x-2011=2
a^2+b^2=4028
(a+b)^2-2ab=2048
2^2-2ab=2048
-2ab=2044
-ab=1022
-(2013-x)(x-2011)=1022
(2013-x)(2011-x)=-1022
设(2013-x)=a,(x-2011)=b,
则a²+b²=4028,且a+b=(2013-x)+(x-2011)=2,
∵(a+b)²=a²+2ab+b²
∴ab=[(a+b)²-(a²+b²)]/2=(2²-4028)/2=-2012
即(2013-x)(2011-x)的值为-2012.