Những câu hỏi liên quan
5^2/1x6+5^2/6x11+5^2/11x16+5^/16x21+5^2/21x26+5^2/26x31
tinh hop ly
Tính tổng sau:
5^2/1x6 + 5^2/6x11 +......+ 5^2/26x31
các bạn giúp mình với
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+...+\frac{5^2}{26.31}\)
\(\frac{5^2}{1.6}=5.\left(\frac{1}{1}-\frac{1}{6}\right)\)
\(\frac{5^2}{6.11}=5.\left(\frac{1}{6}-\frac{1}{11}\right)\)
............................
\(\frac{5^2}{26.31}=5.\left(\frac{1}{26}-\frac{1}{31}\right)\)
cộng hết lại: \(5.\left(\frac{1}{1}-\frac{1}{31}\right)=5\left(\frac{30}{31}\right)=\frac{150}{31}\)
Đúng 1
Bình luận (0)
Ta có :
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+...+\frac{5^2}{26.31}\)
\(=\)\(5\left(\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+...+\frac{5}{26.31}\right)\)
\(=\)\(5\left(\frac{1}{1}-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+...+\frac{1}{26}-\frac{1}{31}\right)\)
\(=\)\(5\left(1-\frac{1}{31}\right)\)
\(=\)\(5-\frac{5}{31}\)
\(=\)\(\frac{150}{31}\)
Chúc bạn học tốt ~
Đúng 2
Bình luận (0)
Ta có : 521.6+526.11+5211.16+...+5226.31521.6+526.11+5211.16+...+5226.31 ==5(51.6+56.11+511.16+...+526.31)5(51.6+56.11+511.16+...+526.31) ==5(11−16+16−111+111−116+...+126−131)5(11−16+16−111+111−116+...+126−131) ==5(1−131)5(1−131) ==5−5315−531 ==15031 |
Đúng 0
Bình luận (0)
TÍNH NHANH
A= 5/1x6 + 5/6x11 + 5/11x16 +.........+ 5/26x31
\(A=\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+...+\frac{1}{26.31}\)
\(=1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+\frac{1}{16}+...+\frac{1}{26}-\frac{1}{31}\)
\(=1+\left(-\frac{1}{6}+\frac{1}{6}\right)+\left(-\frac{1}{11}+\frac{1}{11}\right)+...+\left(-\frac{1}{26}+\frac{1}{26}\right)-\frac{1}{31}\)
\(=1-\frac{1}{31}=\frac{31-1}{31}\)
\(=\frac{30}{31}\)
Vậy \(A=\frac{30}{31}\)
Đúng 0
Bình luận (0)
\(A=\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+...+\frac{5}{26.31}\)
\(\Rightarrow A=\frac{1}{1}-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+...+\frac{1}{26}-\frac{1}{31}\)
\(\Rightarrow A=\frac{1}{1}-\frac{1}{31}\)
\(\Rightarrow A=\frac{30}{31}\)
Đúng 0
Bình luận (0)
TÍNH NHANH
A= 5/1x6 + 5/6x11 + 5/11x16 +.........+ 5/26x31
BẠN NÀO BIẾT HÃY GIẢI MÌNH NGAY NHÉ !
CẢM ƠN CÁC BẠN !
\(\Rightarrow A=1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+.....+\frac{1}{26}-\frac{1}{31}\)
\(\Rightarrow A=1-\frac{1}{31}\)
\(\Rightarrow A=\frac{30}{31}\)
Đúng 0
Bình luận (0)
\(A=\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+...+\frac{5}{26.31}\)
\(=1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+...+\frac{1}{26}-\frac{1}{31}\)
\(=1+\left(-\frac{1}{6}+\frac{1}{6}\right)+\left(-\frac{1}{11}+\frac{1}{11}\right)+...+\left(-\frac{1}{26}+\frac{1}{26}\right)-\frac{1}{31}\)
\(=1-\frac{1}{31}=\frac{31-1}{31}=\frac{30}{31}\)
\(\text{Vậy }A=\frac{30}{31}\).
Đúng 0
Bình luận (0)
A = \(\frac{5}{1x6}+\frac{5}{6x11}+\frac{5}{11x16}+...+\frac{5}{26x31}\)
A= \(\frac{1}{1}-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+...+\frac{1}{26}-\frac{1}{31}\)
A = \(\frac{1}{1}-\frac{1}{31}=\frac{31}{31}-\frac{1}{31}=\frac{30}{31}\)
Đúng 0
Bình luận (0)
tính nhanh 5^2/5x6+5^2/6x11+5^2/16x21+5^2./21x26+5^2/26x31+5^2/31x36 giúp mk nha. mk tích cho
mk chỉnh lại đề nhé, có lẽ bn ghi thiếu:
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}+\frac{5^2}{31.36}\)
\(=5\left(\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+...+\frac{5}{26.31}+\frac{5}{31.36}\right)\)
\(=5\left(1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+...+\frac{1}{26}-\frac{1}{31}+\frac{1}{31}-\frac{1}{36}\right)\)
\(=5\left(1-\frac{1}{36}\right)=5.\frac{35}{36}=\frac{175}{36}\)
Đúng 0
Bình luận (0)
Đề đúng:
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}+\frac{5^2}{26.31}+\frac{5^2}{31.36}\)
\(=5\left(\frac{5}{1.6}+\frac{5}{6.11}+\frac{5}{11.16}+\frac{5}{16.21}+\frac{5}{21.26}+\frac{5}{26.31}+\frac{5}{31.36}\right)\)
\(=5\left(1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+\frac{1}{16}-\frac{1}{21}+\frac{1}{21}-\frac{1}{26}+\frac{1}{26}-\frac{1}{31}+\frac{1}{31}-\frac{1}{36}\right)\)
\(=5\left(1-\frac{1}{36}\right)\)
\(=5\left(\frac{36}{36}-\frac{1}{36}\right)\)
\(=5.\frac{35}{36}\)
\(=\frac{175}{36}\)
Đúng 0
Bình luận (0)
5^2/1x6+5^2/6x11+5^2/11x16+5^2/16x21+5^2/21x26
\(\frac{5^2}{1.6}+\frac{5^2}{6.11}+\frac{5^2}{11.16}+\frac{5^2}{16.21}+\frac{5^2}{21.26}\)
\(=5^2\left(\frac{1}{1.6}+\frac{1}{6.11}+\frac{1}{11.16}+\frac{1}{16.21}+\frac{1}{21.26}\right)\)
\(=25.\frac{1}{5}\left(1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+...+\frac{1}{21}-\frac{1}{26}\right)\)
\(=5\left(1-\frac{1}{26}\right)\)
\(=5.\frac{25}{26}\)
\(=\frac{125}{26}\)
Đúng 0
Bình luận (0)
5^2/1x6+5^2/6x11+5^2/11x16+5^2/16x21+5^2/21x26
làm giúp mình nha .tính nhanh 5^2/5x6+5^2/6x11+5^2/16x21+5^2./21x26+5^2/26x31+5^2/31x36
521x6 + 52/6x11 + ......+ 52/201.206
ko tin là học lớp 1 đâu (lớp 1 ko đc học cái này)