\((1)-\dfrac{1}{3}πa^{3}bx^{2}\) 的系数为______,次数为________
\((2)\)若单项式\( \dfrac{5}{7} ax^{2}y^{n+1}\)与\(- \dfrac{7}{5} ax^{m}y^{4}\)的差仍是单项式,则\(m-2n=\)_______.
\((3)\)请你写出一个大于\(0\)且小于\(3\)的无理数为_______.
\((4)\)在函数\(y= \dfrac{ \sqrt{x+1}}{x} \)中,自变量\(x\)的取值范围是___________
\((5)\)若一个正数的两个平方根分别是\(a-5\)和\(2a-4\),则这个正数为___________.
\((6)\)已知整式\(x^{2}-2x+1\)的值为\(5\),则整式\(-2x^{2}+4x+6\)的值为__.
\((7)\)已知:如图,在\(⊙O\)中,弦\(AB\)、\(CD\)相交于点\(P\),\(PA=2\),\(PB=6\),\(PC=3\),则\(CD=\)_____.
\((8)\)已知\(4×8^{m}×16^{m}=2^{9}\),则\(m=\)______________
\((9)\)分解因式:\(x^{3}-8x\)_________________
\((10)(-\dfrac{1}{2})^{2017}×2^{2018\;}=\)___________
\((11)\)已知多项式\(x^{2}+kx+ \dfrac{1}{4} \)是一个完全平方式,则\(k\)的值为_____________
\((12)\)若\( \dfrac{1}{(2n-1)(2n+1)}= \dfrac{a}{2n-1}+ \dfrac{b}{2n+1} \),对任意自然数\(n\)都成立,则\(a-b=\)____.
\((13)\)一组按规律排列的数:\(\dfrac{1}{3}\),\(\dfrac{3}{8}\),\(\dfrac{7}{15}\),\(\dfrac{13}{24}\),\(\dfrac{21}{35}…..\)则第\(10\)个数是_______
\((14)\)如图,数轴上点\(A\)表示的实数是__________.