a Find the critical numbers b open intervals where the funct

(a) Find the critical numbers, (b) open intervals where the function is increasing and (c) open intervals where the function is decreasing.
f(x) = (x+3)/(x-5).

(a)the critical no is x-5 = 0 => x=5 (b) functtion increasing => denominator decreases => x-5 < 0 =>x<5 =>x belongs to (-infinity , 5) (c)functtion decreasing => denominator increases => x-5 > 0 =>x>5 =>x belongs to (5,infinity)