Question

limстремится к 3 x^2-2x-3/x^2-9

Answer 1

x²-2x-3=(x-3)(x+1)
x²-9=(x-3)(x+3)
Поэтому
$lim_{x to 3} frac{x^2-2x-3} {x^2-9} = lim_{x to 3} frac{(x-3)(x+1)} {(x-3)(x+3)} = lim_{x to 3} frac{x+1} {x+3} = frac{3+1} {3+3} = frac{4} {6} =frac{2} {3}$