Question

[Nguyen Bao Khanh]

Bai 2. Tim x:

a) x : 0,25 + x . 11 = 24                                                  b) x . 8,01 - x : 100 = 38

c) 2,3 : 2,8 . x =57,5                                                      d) 0,16 : (x : 3,5) = 2,8

Answer 1

[Pham Minh Hiển]

a)x/0.25+x*11=24

x*4+x*11=24

x*(4+11)=24

x*15=24

x=24/15

b)

Answer 2

[Huỳnh Quang Sang]

a) \(x:0,25+x\cdot11=24\)

=> \(x:\frac{25}{100}+x\cdot11=24\)

=> \(x:\frac{1}{4}+x\cdot11=24\)

=> \(x\cdot4+x\cdot11=24\)

=> x(4 + 11) = 24

=> x . 15 = 24

=> x = 24/15

b) x . 8,01 - x : 100 = 38

=> x . 8,01 - x . \(\frac{1}{100}\)= 38

=> x(8,01 - \(\frac{1}{100}\)) = 38

=> x.8 = 38

=> x = \(\frac{38}{8}=\frac{19}{4}\)

c) 2,3 : 2,8.x = 57,5

=> \(\frac{23}{10}:\frac{28}{10}x=57,5\)

=> \(\frac{23}{10}\cdot\frac{10}{28}x=\frac{115}{2}\)

=> \(\frac{23}{28}x=\frac{115}{2}\)

=> \(x=\frac{115}{2}:\frac{23}{28}=\frac{115}{2}\cdot\frac{28}{23}=70\)

d) 0,16 : (x : 3,5) = 2,8

=> x : 3,5 = 0,16 : 2,8

=> x : 3,5 = \(\frac{2}{35}\)

=> x = \(\frac{2}{35}\cdot3,5=\frac{2}{35}\cdot\frac{35}{10}=\frac{1}{5}\)

P/S : Lớp 5 có dấu " ." ?