PLEASE HELP!!!!!matematika :(

PLEASE HELP!!!!!matematika :(

$a. frac{1}{1 times 2} + frac{2}{3 times 4} + frac{3}{4 times 9} \ = frac{1}{2} + frac{2}{12} + frac{3}{36} \ = frac{18}{36} + frac{6}{36} + frac{3}{36} \ = frac{27}{36} = frac{3}{4}$

$b. frac{1}{6} + frac{2}{120} + frac{3}{360} \ = frac{60}{360} + frac{6}{360} + frac{3}{360} \ = frac{69}{360} = frac{23}{120}$

Note : nilai mutlak selalu berniIai positif.

Semoga membantu, jadikan yang tercerdas ya!