Tolong bantu dong kak beserta caranya

Tolong bantu dong kak beserta caranya

Deret Teleskopik

$frac{1}{2 times 3} + frac{1}{3 times 4} + frac{1}{4 times 5} + ... + frac{1}{99 times 100} = n\\(frac{1}{2} - frac{1}{3})+(frac{1}{3} - frac{1}{4}) + (frac{1}{4} - frac{1}{5}) + ... + (frac{1}{99} - frac{1}{100}) = n\\frac{1}{2} - frac{1}{3} + frac{1}{3} - frac{1}{4} + frac{1}{4} - frac{1}{5} + frac{1}{5} - ...-frac{1}{99} + frac{1}{99} - frac{1}{100} = n\\frac{1}{2} - frac{1}{100} = n\$

maka :

$frac{1}{2} - n\\= frac{1}{2} - (frac{1}{2} - frac{1}{100})\\= frac{1}{2} - frac{1}{2} + frac{1}{100}\\= frac{1}{100}$

Jawaban A