Question

Tìm số tự nhiên x, biêt:

a, 219 - 7(x + 1) = 100

b, (3x - 6) . 3 = 3⁴

Answer 1

a)

\(219-7\left(x+1\right)=100\)

\(\Rightarrow7\left(x+1\right)=119\)

\(\Rightarrow x+1=17\)

=> x = 16

Vậy x = 16

b)

\(\left(3x-6\right)3=3^4\)

\(\Rightarrow\left(x-2\right)3^2=3^4\)

=> x - 2 = 9

=> x = 7

Vậy x = 7

Answer 2

Giải:

a, 219 - 7(x + 1) = 100

7(x + 1) = 219 - 100

7(x + 1) = 119

x + 1 = 119 : 7

x + 1 = 17

x = 17 - 1

x = 16

Answer 3

b, (3x - 6) . 3 = 3⁴

(3x - 6) . 3 = 81

3x - 6 = 81 : 3

3x - 6 = 27

3x = 27 + 6

3x = 33

x = 33 : 3

x = 11

Answer 4

a, 219 - 7(x + 1) = 100

7( x + 1 ) = 219 - 100

7( x+1 ) = 119

x + 1 = 119 : 7

x + 1 = 17

x = 17 - 1

x = 16.

 

b, (3x - 6) . 3 = 3⁴

( 3x - 6 ) . 3= 81

3x- 6 = 81 : 3

3x - 6 = 27

3x = 27 + 6

3x = 33

x = 33 : 3

x = 11.

Chúc bn học tốt

 

Answer 5

a,219-7(x+1)=100

7(x+1)=219-100

7(x+1)=119

x+1=119:7

x+1=17

x=17-1

x=16

Answer 6

b,(3x-6).3=3⁴

(3x-6)=3⁴:3

(3x-6)=3³=27

3x=27+6

3x=33

x=33:3

x=11

Answer 7

a) 219 - 7(x + 1) = 100

\(\Rightarrow\) 7(x + 1) = 219 - 100 = 119

\(\Rightarrow\) x + 1 = \(\frac{119}{7}\) = 17

\(\Rightarrow\) x = 16

Vậy x = 16

b) (3x - 6) . 3 = 3⁴

\(\Rightarrow\) 3x - 6 = 3⁴ : 3

\(\Rightarrow\) 3x - 6 = 3³ = 27

\(\Rightarrow\) 3x = 27 + 6 = 33

\(\Rightarrow\) x = 11

Vậy x = 11