Find ∫12(3x+1x)2 dx\displaystyle\int_1^2\left(3x+\frac1x\right)^2\,dx∫12(3x+x1)2dx. A13.513.513.5B14.7514.7514.75C21.521.521.5D26.526.526.5E27.527.527.5F28.7528.7528.75