Question

Tính nhanh 

C = 1/2 + 1/14 + 1/35 + 1/65 + 1/104 + 1/152

Answer 1

\(C=\frac{1}{2}+\frac{1}{14}+\frac{1}{35}+\frac{1}{65}+\frac{1}{104}+\frac{1}{152}\)

\(C=\frac{1}{1.2}+\frac{1}{2.7}+\frac{1}{7.5}+\frac{1}{5.13}+\frac{1}{13.8}+\frac{1}{8.19}\)

\(C=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{7}+\frac{1}{7}-\frac{1}{5}+\frac{1}{5}-\frac{1}{13}+\frac{1}{31}-\frac{1}{8}+\frac{1}{8}-\frac{1}{19}\)

( GẠCH BỎ CÁC PHÂN SỐ GIỐNG NHAU )

\(C=1-\frac{1}{19}\)

\(C=\frac{18}{19}\)

CHÚC BN HỌC TỐT!!!!!!!