Suppose that y varies inversely as x, and x=9 when y=15. Find the value for k and write the function. Group of answer choices LaTeX: k=\frac{15}{9} k = 15 9 k = 15 9 and LaTeX: y=\frac{9}{15}x y = 9 15 x y = 9 15 x LaTeX: k=\frac{15}{9} k = 15 9 k = 15 9 and LaTeX: y=\frac{15}{9x} y = 15 9 x y = 15 9 x LaTeX: k=135 k = 135 k = 135 and LaTeX: y=\frac{135}{x} y = 135 x y = 135 x LaTeX: k=135 k = 135 k = 135 and LaTeX: y=135x