Question

Tìm x:

a) 100 - 7 . (x - 5) = 58

b) \(x+\frac{1}{3}=\frac{7}{26}.\frac{13}{6}\)

c) \(\left(\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+..........+\frac{1}{97.100}\right)x=\frac{98}{100}\)

 

Answer 1

a) 100 - 7 . (x - 5) = 58

7. (x - 5) = 100 - 58

7. (x - 5) = 42

x - 5 = 42 : 7

x - 5 = 6

x = 6 + 5 

x = 11

b)\(x+\frac{1}{3}=\frac{7}{26}.\frac{13}{6}\)

\(x+\frac{1}{3}=\frac{7}{12}\)
\(x=\frac{7}{12}-\frac{1}{3}\)

\(x=\frac{3}{12}=\frac{1}{4}\)

Answer 2

Thiếu câu c) bạn ơi!

Answer 3

ok trả lời liền

Answer 4

Ừm mk đang gấp lắm

Answer 5

c)\(\left(\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+............+\frac{1}{97.100}\right)x=\frac{98}{100}\)

\(\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+...........+\frac{1}{97}-\frac{1}{100}\right)=\frac{98}{100}:x\)

\(\left(\frac{1}{2}-\frac{1}{100}\right)=\frac{98}{100}:x\)

\(\frac{49}{100}=\frac{98}{100}:x\)

\(x=\frac{98}{100}:\frac{49}{100}\)

x =2

Answer 6

ê sai rùi

Answer 7

@ Nguyen Chau Tuan Kiet @ Làm sai câu c rồi !

\(c,\text{ }\left(\frac{1}{2\cdot5}+\frac{1}{5\cdot8}+\frac{1}{8\cdot11}+...+\frac{1}{97\cdot100}\right)\cdot x=\frac{98}{100}\)

\(\frac{1}{3}\left(\frac{3}{2\cdot5}+\frac{3}{5\cdot8}+\frac{3}{8\cdot11}+...+\frac{3}{97\cdot100}\right)\cdot x=\frac{98}{100}\)

\(\frac{1}{3}\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+...+\frac{1}{97}-\frac{1}{100}\right)\cdot x=\frac{98}{100}\)

\(\frac{1}{3}\cdot\left(\frac{1}{2}-\frac{1}{100}\right)\cdot x=\frac{98}{100}\)

\(\frac{1}{3}\cdot\frac{98}{100}\cdot x=\frac{98}{100}\)

\(\frac{98}{300}\cdot x=\frac{98}{100}\)

\(x=\frac{98}{100}\text{ : }\frac{98}{300}\)

\(x=3\)

Answer 8

Ukm Shizu

\(c,\text{ }\left(\frac{1}{2\cdot5}+\frac{1}{5\cdot8}+\frac{1}{8\cdot11}+...+\frac{1}{97\cdot100}\right)\cdot x=\frac{98}{100}\)

\(\frac{1}{3}\left(\frac{3}{2\cdot5}+\frac{3}{5\cdot8}+\frac{3}{8\cdot11}+...+\frac{3}{97\cdot100}\right)\cdot x=\frac{98}{100}\)

\(\frac{1}{3}\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+...+\frac{1}{97}-\frac{1}{100}\right)\cdot x=\frac{98}{100}\)

\(\frac{1}{3}\cdot\left(\frac{1}{2}-\frac{1}{100}\right)\cdot x=\frac{98}{100}\)

\(\frac{1}{3}\cdot\frac{98}{100}\cdot x=\frac{98}{100}\)

\(\frac{98}{300}\cdot x=\frac{98}{100}\)

\(x=\frac{98}{100}\text{ : }\frac{98}{300}\)

\(x=3\)