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            • 1.
              如果把\( \dfrac {2x}{2x+3y}\)中的\(x\)、\(y\)都扩大\(5\)倍,那么分式的值\((\)  \()\)
              A.扩大\(5\)倍
              B.不变
              C.缩小\(5\)倍
              D.扩大\(4\)倍
            • 2.

              下列式子从左到右的变形一定正确的是

              A.\(\dfrac{a+3}{b+3}=\dfrac{a}{b}\)
              B.\(\dfrac{a}{b}=\dfrac{ac}{bc}\)       
              C.\(\dfrac{3a}{3b}=\dfrac{a}{b}\)
              D.\(\dfrac{a}{b}=\dfrac{{{a}^{2}}}{{{b}^{2}}}\)
            • 3.

              下列各式中,正确的是(    )

              A.\(- \dfrac{-3x}{5y}= \dfrac{3x}{-5y}\)
              B.\(- \dfrac{a+b}{c}= \dfrac{-a+b}{c}\)

              C.\( \dfrac{-a-b}{c}= \dfrac{a-b}{c}\)
              D.\(- \dfrac{a}{b-a}= \dfrac{a}{a-b}\)
            • 4.

              已知\(\dfrac{x}{3}=\dfrac{y}{4}=\dfrac{z}{5}\ne 0\)  ,则\(\dfrac{2x-y}{x+2y-3z}=\)__________.

            • 5.

              如果把分式\(\dfrac{3{{x}^{2}}}{2y}\)中的\(x\)和\(y\)都扩大为原来的\(5\)倍,那么分式的值\((\)     \()\)          

              A.扩大为原来的\(5\)倍                     
              B.扩大为原来的\(10\)倍 
              C.不变                                 
              D.缩小为原来的\(\dfrac{1}{5}\)倍
            • 6.
              下列各式中,从左到右变形正确的是\((\)  \()\)
              A.\( \dfrac {b}{a}= \dfrac {b^{2}}{a^{2}}\)
              B.\( \dfrac {a^{2}+b^{2}}{a+b}=a+b\)
              C.\( \dfrac {1}{-x+y}=- \dfrac {1}{x-y}\)
              D.\( \dfrac {2y}{2x+y}= \dfrac {y}{x+y}\)
            • 7.
              分式\( \dfrac {xy}{x+y}\)中的\(x\),\(y\)都扩大\(2\)倍,则分式的值\((\)  \()\)
              A.不变
              B.扩大\(2\)倍
              C.扩大\(4\)倍
              D.缩小\(2\)倍
            • 8.

              下列各式从左到右的变形正确的是

              A.\(\dfrac{x-\dfrac{1}{2}y}{\dfrac{1}{2}x+y}=\dfrac{2x-y}{x+2y}\)
              B.\(\dfrac{0.2a+b}{a+0.2b}=\dfrac{2a+b}{a+2b}\)
              C.\(-\dfrac{x+1}{x-y}=\dfrac{x-1}{x-y}\)
              D.\(\dfrac{a+b}{a-b}=\dfrac{a-b}{a+b}\)
            • 9.
              如果把分式\( \dfrac {2n}{m^{2}-n^{2}}\)中的\(m\)和\(n\)都扩大\(2\)倍,那么分式的值\((\)  \()\)
              A.不变
              B.扩大\(2\)倍
              C.缩小\(2\)倍
              D.扩大\(4\)倍
            • 10.

              若\(3x-2y=0\),则\(\dfrac{x}{y}+1\)等于          

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