Question

Tìm số tự nhiên x, biết:

a) 541 + (218 - x) = 735;                                       b) 5(x + 35) = 515;

c) 96 - 3(x + 1) = 42;                                            d) 12x - 33 = 3² . 3³.

Answer 1

a, 541 + ( 218 - x ) = 735

( 218 - x ) = 735 - 541 

218 - x = 194

=> x = 218 - 194 

=> x = 24

Vậy x = 24

b, 5 ( x + 35 ) = 515

( x + 35 ) = 515 : 5

x + 35 = 103

=> x = 103 - 35

=> x = 68

Vậy x = 68

c, 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

d, 12x - 33 = 3² . 3³

12x - 33 = 9 . 27

12x - 33 = 243

12x = 243 + 33

12x = 276

=> x = 276 : 12

=> x = 23

Vậy x = 23

Answer 2

a, =22

b, =138

 

Answer 3

a) \(541+\left(218-x\right)=735\)

\(218-x=735-541=194\)

\(x=218-194=24\)

b) \(5\left(x+35\right)=515\)

\(x+35=515:5=103\)

\(x=103-35=68\)

c) \(96-3\left(x+1\right)=42\)

\(3\left(x+1\right)=96-42=54\)

\(x+1=54:3=18\)

\(x=18-1=17\)

d) \(12x-33=3^2\cdot3^3\)

\(12x-33=243\)

\(12x=243+33=276\)

\(x=276:12=23\)

 

Answer 4

a) 541 + ( 218 - x ) = 735

218 - x = 735 - 541

218 - x = 196

x = 218 - 196

x = 22

Vậy x = 22

Answer 5

b) 5 ( x + 35 ) = 515

x + 35 = 515 : 5

x + 35 = 103

x = 103 - 35

x = 68

Vậy x = 68

c) 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

Vậy x = 17

d) 12x - 33 = 3² . 3³

\(\Rightarrow\) 12x - 33 = 243

12x = 243 + 33

12x = 276

x = 276 : 12

x = 23

Vậy x = 23