Question

B= \(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+...+\frac{5^2}{26.31}\)

 

Answer 1

Vì: 5²=5.5

= \(5.\left(\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+...+\frac{5}{26.31}\right)\)

= \(5.\left(\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+...+\frac{1}{26}-\frac{1}{31}\right)\)

= \(5.\left(1-\frac{1}{31}\right)\)

= \(5.\frac{30}{31}\)

= \(\frac{150}{31}\)

Answer 2

\(B=\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+...+\frac{5^2}{26.31}\)

\(B=5\left(\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+...+\frac{5}{26.31}\right)\)

\(B=5\left(1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+...+\frac{1}{26}-\frac{1}{31}\right)\)

\(B=5\left(1-\frac{1}{31}\right)\)(TỐI GIẢN CÁC PHÂN SỐ GIỐNG NHAU)

\(B=5.\frac{30}{31}\)

\(B=\frac{150}{31}\)

Answer 3

trả lời nhah ha, mk chỉ chọn có 4 câu trả lời thui!

Answer 4

=150/31 tk minh nha

Answer 5

150/31 nha bn

k giùm mk nha các bn

>_< học tốt

Answer 6

\(\frac{150}{31}\)nhé

Answer 7

150/31 nha