Step 1 :\(\left(\frac{d^{6}}{d^{-7}}\right)^{\frac{4}{39}} = \left(d^{(6 + 7)}\right)^{\frac{4}{39}}\)
Step 2 :\(= \left(d^{13}\right)^{\frac{4}{39}}\)
Step 3 :\(= d^{\frac{52}{39}}\)