lim x->16 4- sqrt(x) / x-16

Answer 1

Did you realize that
x-16 = (√x+4)(√x-4) ?

then your limit question simplifies to

lim (4-√x)/( (√x+4)(√x-4) ) as x --> 16
= lim -1/(√x+4) as x --> 16
= -1/8