The value of \(\frac{\sin^3A-\cos^3A}{1+\sin A\cdot\cos A}\) + 2 sin²54° sec²36° is:
sin A + cos A − 2
2(1 + sin A · cos A)
sin A − cos A + 2
sin A · cos A + 2
Shifa can do a certain piece of work in 20 days. Shifa and Afiya can together do the same work in 12 days, and Shifa, Afiya and Mariyam can do the same work together in 9 days. In how many days can Shifa and Mariyam do the same work together?
\( \frac{83}{8} \)
\( \frac{85}{9} \)
\( \frac{90}{7} \)
\( \frac{80}{7} \)