Question 809880


{{{7 sin^-1 (x) - 4pi = 5 sin^-1 (x) - 5pi}}}


{{{7 sin^-1 (x) - 5 sin^-1 (x) = 4pi - 5pi}}}

{{{2 sin^-1 (x) =  - pi}}}

{{{sin^-1 (x) =  - pi/2}}}

{{{x=-1}}}