Answer
$\dfrac{15}{2x^3}$
Work Step by Step
RECALL:
$(f\cdot g)(x) = f(x)\cdot g(x)$
Using the formula above gives:
$(r\cdot t)(x)
\\= r(x)\cdot t(x)
\\=\dfrac{5}{x^2} \cdot \dfrac{3}{2x}
\\=\dfrac{5(3)}{x^2(2x)}
\\=\dfrac{15}{2x^3}$