limit as n approaches infinity for the function ((-1)^n)((5n+7)/(6n+5))

multiply both numerator and denominator by 1/n

then
Lim (-1)^n (5+7/n)/(6+5/n)

so as n gets large, the second part becomes (5/6)
the first part is +-1, depending if n is odd or even.

there is not a limit. however, the funcion is +- 5/6 and is bounded by those two numbers.