Question

3. Tìm X thuộc N biết : 

a) 135 - (x+ 37) = 80 

b) (x - 17) + 52 = 735

c) 541 + (218 - x ) = 735 

d) 96 - 3 (x + 1) = 42 

e) (x- 47) - 115 = 0 

f) (x- 36 ) : 18 = 12

 

Answer 1

a) 135 - ( x + 37 ) = 80

( x + 37 ) = 135 - 80

( x + 37 ) = 55

x = 55 - 37

x = 18

b) ( x - 17 ) + 52 = 158

( x - 17 ) = 158 - 52

( x - 17 ) = 106

x = 106 + 17

x = 123

c) 541 + ( 218 - x ) = 735

218 - x = 735 - 541

218 - x = 194

x = 218 - 194

x = 24

d) 96 - 3.(x + 1) = 42

3.(x + 1)= 96 - 42

3.(x + 1) = 54

x + 1= 54:3

x + 1= 18

x = 18 - 1

x = 17

e) (x-47)-115=0

x-47=0+115

x-47=115

x=115+47

x=162

f) (x – 36) : 18 = 12

x – 36 = 12.18

x – 36 = 216

x = 216 + 36

x = 252