下列计算或化简正确的是[]A．a2+a3=a5B．C．D．-九年级数学

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• 如果,那么A=（）-八年级数学
• 分式的基本性质：分式的分子、分母同乘（或除以）同一个（），分式的值不变，分式的符号法则：分式的分子、分母及分式本身，三者的符号改变其中（）分式的值不变。-八年级数学
• （m≠0）[]-八年级数学
• Hannah ________me; otherwise, other students wouldn't have known my result of the quiz.[ ]A. ma
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• 小明、小华、小颖三名同学解这样一个问题：求a为何值时，成立．小明：因为a2+2a﹣3=（a﹣1）（a+3），从分式的右边知，分式的分子和分母同时除以a﹣1，只需a﹣1≠0即可，故a的取值范围是-八年级
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• 把分式中的x和y都扩大为原来的5倍，这个分式的值[]A.扩大为原来的5倍B.缩小了5倍C.不变D.扩大为原来的2.5倍-八年级数学
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• 不改变分式的值，如果把其分子和分母中的各项的系数都化为整数，那么所得的正确结果为[]A．B．C．D．-八年级数学
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