Evaluate

Question

lim x-->25

5 - square root x / x - 25

I don't get how the answer is -1/10

Answer 1

lim (5 - √x)/(x-25) as x ---> 25
= lim (5-√x)/((√x-5)(√x+5))
= lim -1/(√x+5) as x ---> 25
= -1/(5+5)
= -1/10