7.
\((1)\)若\( \dfrac{a+2b}{2a-b}= \dfrac{9}{5} \),则\( \dfrac{a}{b} =\)_________
\((2)Rt\triangle ABC\)中,\(∠C=90^{\circ}\),\(\cos A= \dfrac{5}{13} \),则\(\sin A= \)________.
\((3)\)若\(M(- \dfrac{1}{2},{y}_{1} )\)、\(N(- \dfrac{1}{4},{y}_{2} )\)、\(P( \dfrac{1}{2},{y}_{3} )\)三点都在函数\(y= \dfrac{k}{x} (k < 0)\)的图象上,则\({y}_{1},{y}_{2},{y}_{3} \)的大小关系为________________ \((\)用“\( > \)”连接\()\)
\((4)\)如图,\(Rt\triangle ABC\)中,\(∠ACB=90^{\circ}\),\(BC=6\),\(AC=8\),现将\(\triangle ABC\)折叠,使点\(A\)与点\(B\)重合,折痕为\(DE\),则\(t an∠CBE= \)________.