We are asked to find the coefficient of the 6th term, which means we need to find the value of r when r+1=6, or r=5. Substituting r=5 into the general term formula, we get: T6=‌10C5x0sin‌5x=‌10C5sin‌5x We are told that this coefficient is equal to 7‌
7
8
, so we have the equation: ‌10C5sin‌5x=7‌
7
8
=‌
63
8
Now, we need to find the value of x that satisfies this equation. We can use a calculator to find the value of ‌10C5=252. Therefore: ‌252sin‌5x=‌