\(
7.5 \times 17.2 \div 8.6 \;+\; (59.5)\ of \frac{1}{17} \;-\; \frac{7}{2}\ of 5 \;=\; ?
\)
If (5y + 5/y) = 11, find the value of
\(
\left(y^{2}+\frac{1}{y^{2}}\right)
\)
\(
\frac{2\tan A}{1+\tan^{2}A}=?
\)
Find the value of sin(50 + θ) - cos(40 - θ).