Question

Tìm x:

15.x+15.2,7=105

x:7=920699:70

5.x-1952=2500-1947

x.2016-x=2016.2017+2016

Answer 1

a)15.x+15.2,7=105

15.(x+2,7)=105

x+2,7=7

x=7-2,7

x=4,3

Vậy x=4,3

b)x:7=920699:70

x:7=920699:10:7

x:7=92069,9:7

x=92069,9

Vậy x=92069,9

c)5.x-1952=2500-1947

  5.x-1952=553

 5.x=2505

 x=501

Vậy x=501

d)x.2016-x=2016.2017+2016

  x.(2016-1)=2016.(2017+1)

 x.2015=2016.2018

x=\(\frac{2016.2018}{2015}\)

Vậy x\(\frac{2016.2018}{2015}\)

Answer 2

15.x+15.2,7=105
<=> 15.( x + 2,7 ) = 105 
=> x + 2,7 = 7
=> x = 7 - 2,7 
=> x = 4,3

x:7=920699:70
<=> x . 70 = 920699 . 7 
=> x . 70 = 6444893
=> x = 6444893 : 70 
=> x = 92069,9

5.x-1952=2500-1947
=> 5x - 1952 = 553
=> 5x = 553 + 1952 
=> 5x = 2505 
=> x = 2505 : 5 
=> x = 501 

x.2016-x=2016.2017+2016
=> x ( 2016 - 1 ) = 2016 ( 2017 + 1) 
=> x . 2015 = 2016 . 2018 
=> x : 2018 = 2016 : 2015 
=> x : 2018 = \(\frac{2016}{2015}\)
=> x = \(\frac{2016}{2015}.2018\approx2019\)