($\frac{1}{4.9}$+$\frac{1}{9.14}$+$\frac{1}{14.19}$+…+$\frac{1}{44.49)}$.$\frac{1-3-5-7-…-49}{89}$ 04/12/2021 Bởi Charlie ($\frac{1}{4.9}$+$\frac{1}{9.14}$+$\frac{1}{14.19}$+…+$\frac{1}{44.49)}$.$\frac{1-3-5-7-…-49}{89}$
($\frac{1}{4.9}$+ $\frac{1}{9.14}$+$\frac{1}{14.19}$+…+ $\frac{1}{44.49}$).$\frac{1-3-5-7-…-49}{89}$ =$\frac{5}{5}$.($\frac{1}{4.9}$+ $\frac{1}{9.14}$+$\frac{1}{14.19}$+…+ $\frac{1}{44.49}$).$\frac{-623}{89}$ =$\frac{1}{5}$.($\frac{5}{4.9}$+ $\frac{5}{9.14}$+$\frac{5}{14.19}$+…+ $\frac{5}{44.49}$).$\frac{-623}{89}$ =$\frac{1}{5}$.($\frac{1}{4}$-$\frac{1}{9}$+$\frac{1}{9}$-…+$\frac{1}{14}$-$\frac{1}{49}$ ).$\frac{-623}{89}$ =$\frac{1}{5}$.($\frac{1}{4}$- $\frac{1}{49}$).$\frac{-623}{89}$ =$\frac{1}{5}$.$\frac{45}{196}$.$\frac{-623}{89}$ =$\frac{9}{196}$.$\frac{-623}{89}$ =$\frac{-9}{28}$ Bình luận
($\frac{1}{4.9}$+ $\frac{1}{9.14}$+$\frac{1}{14.19}$+…+ $\frac{1}{44.49}$).$\frac{1-3-5-7-…-49}{89}$
=$\frac{5}{5}$.($\frac{1}{4.9}$+ $\frac{1}{9.14}$+$\frac{1}{14.19}$+…+ $\frac{1}{44.49}$).$\frac{-623}{89}$
=$\frac{1}{5}$.($\frac{5}{4.9}$+ $\frac{5}{9.14}$+$\frac{5}{14.19}$+…+ $\frac{5}{44.49}$).$\frac{-623}{89}$
=$\frac{1}{5}$.($\frac{1}{4}$-$\frac{1}{9}$+$\frac{1}{9}$-…+$\frac{1}{14}$-$\frac{1}{49}$ ).$\frac{-623}{89}$
=$\frac{1}{5}$.($\frac{1}{4}$- $\frac{1}{49}$).$\frac{-623}{89}$
=$\frac{1}{5}$.$\frac{45}{196}$.$\frac{-623}{89}$
=$\frac{9}{196}$.$\frac{-623}{89}$
=$\frac{-9}{28}$