若x+y=2a,x-y=2b,则x²-y²的值为( ).(1)若x+y=2a,x-y=2b,则x²-y²的值为( ).(2)计算(x²+1/4)(x+1/2)(x-1/2)的结果为( ).(3)下列代数式的值是1的是( ).A.2009²-2008×2010B.2009
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![若x+y=2a,x-y=2b,则x²-y²的值为( ).(1)若x+y=2a,x-y=2b,则x²-y²的值为( ).(2)计算(x²+1/4)(x+1/2)(x-1/2)的结果为( ).(3)下列代数式的值是1的是( ).A.2009²-2008×2010B.2009](/uploads/image/z/14613322-58-2.jpg?t=%E8%8B%A5x%2By%3D2a%2Cx-y%3D2b%2C%E5%88%99x%26%23178%3B%EF%BC%8Dy%26%23178%3B%E7%9A%84%E5%80%BC%E4%B8%BA%EF%BC%88+%EF%BC%89.%EF%BC%881%EF%BC%89%E8%8B%A5x%2By%3D2a%2Cx-y%3D2b%2C%E5%88%99x%26%23178%3B%EF%BC%8Dy%26%23178%3B%E7%9A%84%E5%80%BC%E4%B8%BA%EF%BC%88+%EF%BC%89.%EF%BC%882%EF%BC%89%E8%AE%A1%E7%AE%97%28x%26%23178%3B%2B1%2F4%29%28x%2B1%2F2%29%28x-1%2F2%29%E7%9A%84%E7%BB%93%E6%9E%9C%E4%B8%BA%EF%BC%88+%EF%BC%89.%EF%BC%883%EF%BC%89%E4%B8%8B%E5%88%97%E4%BB%A3%E6%95%B0%E5%BC%8F%E7%9A%84%E5%80%BC%E6%98%AF1%E7%9A%84%E6%98%AF%28+%29.A.2009%26%23178%3B-2008%C3%972010B.2009%26%2317)
若x+y=2a,x-y=2b,则x²-y²的值为( ).(1)若x+y=2a,x-y=2b,则x²-y²的值为( ).(2)计算(x²+1/4)(x+1/2)(x-1/2)的结果为( ).(3)下列代数式的值是1的是( ).A.2009²-2008×2010B.2009
若x+y=2a,x-y=2b,则x²-y²的值为( ).
(1)若x+y=2a,x-y=2b,则x²-y²的值为( ).
(2)计算(x²+1/4)(x+1/2)(x-1/2)的结果为( ).
(3)下列代数式的值是1的是( ).
A.2009²-2008×2010
B.2009²-2009×2010
C.2009²-2009×2008
D.2009²-2008²
若x+y=2a,x-y=2b,则x²-y²的值为( ).(1)若x+y=2a,x-y=2b,则x²-y²的值为( ).(2)计算(x²+1/4)(x+1/2)(x-1/2)的结果为( ).(3)下列代数式的值是1的是( ).A.2009²-2008×2010B.2009
1
若x+y=2a,x-y=2b,
x²-y² 平方差
=(x-y)(x+y)
=2a×2b
=4ab
2
(x²+1/4)(x+1/2)(x-1/2)
=(x²+1/4)[(x+1/2)(x-1/2) ] 平方差
=(x²+1/4)(x²-1/4) 平方差
=x^4-1/16
3
A.2009²-2008×2010
=2009²-(2009-1)×(2009+1) 平方差
=2009²-(2009²-1²)
=1
B.2009²-2009×2010
=2009×(2009-2010)
=-2009
C.2009²-2009×2008
=2009×(2009-2008)
=2009
D.2009²-2008² 平方差
=(2009-2008)(2009+2008)
=4017
选A
4ab
x4-1/16
A
1)x²-y²=(x+y)(x-y)=2a*2b=4ab
若x+y=2a,x-y=2b,则x²-y²的值为(4ab )。
2)(x²+1/4)(x+1/2)(x-1/2)
=(x²+1/4)(x²-1/4)
=x^4-1/16
(x²+1/4...
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1)x²-y²=(x+y)(x-y)=2a*2b=4ab
若x+y=2a,x-y=2b,则x²-y²的值为(4ab )。
2)(x²+1/4)(x+1/2)(x-1/2)
=(x²+1/4)(x²-1/4)
=x^4-1/16
(x²+1/4)(x+1/2)(x-1/2)的结果为(x ^4-1/16 )。
3)A
.2009²-2008×2010
=2009²-(2009-1)(2009+1)
=2009²-(2009²-1)
=2009²-2009²+1=1
收起
(1)x²-y²=(x+y)(x-y)=2a*2b=4ab
(2) 原式=【x²+(1/2)²】【x²-(1/2)²】=x^4-1/16
(3)选A 发现有好详细的解释了 好迟钝的我。。。。