(12 - 3x + 2) x 4 =192

(12-3x+2) = 768

=> (12-3x)=768 ??????

Đến đây hơi vô lí xem lại hộ đề nhá @Trần Ngọc Minh Thư

(12-3x+2).4=192

<=>14-3x=48

<=>3x=-34

<=>x=-34/3

1: =>\(5^{x-2}-9=2^4-\left(6^2-6^2\right)\)

=>\(5^{x-2}=16+9=25\)

=>x-2=2

=>x=4

2: \(\Leftrightarrow3^x+16=19^6:19^5-3=19-3=16\)

=>3^x=0

=>x=0

3: \(\Leftrightarrow2^x+2^x\cdot16=272\)

=>2^x*17=272

=>2^x=16

=>x=4

4: \(\Leftrightarrow2^{x-1}+3=24-\left(4^2-2^2+1\right)=24-\left(16-4+1\right)\)

=>\(2^{x-1}+3=24-16+4-1=8+4-1=12-1=11\)

=>2^x-1=8

=>x-1=3

=>x=4

-24 x 63 + 24 x 21 + (-58) x 24

= 24 x (-63 + 24 + (-58)

= 24 x (-100)

= -2400

k nha

-24 x 63 + 24 x 21 + (-58) x 24

= 24 x (63 + 21 + (-58)

= 24 x (-100)

= -2400

2840 + [ ( 999 - 9 x X ) : 60 ] x 24 = 3200

=> [ ( 999 - 9 x X ) : 60 ] x 24 = 3200 - 2840 = 360

=>    ( 999 - 9 x X ) : 60 = 360  : 24 = 15

= >    999 - 9 x X = 15 x 60 = 900

= >   9 x X = 999 - 900 = 99

=>      X = 99 : 9 = 11

Đúng NHa !!!

2840+[(999-9.x):60].24=3200

[(999-9.x):60].24         = 3200 - 2840

[(999-9.x):60].24         = 360

(999-9.x):60                = 360 : 24

(999-9.x):60                = 15

999-9.x                      = 15 . 60

999-9.x                      = 900

9.x                            = 999 - 900

9.x                            = 99

x                               = 99 : 9

x                                = 11

​Vậy x=1

Đáp án cần chọn là: B

x∈{−1;0;1;2;3;4;5}

5 6 + − 7 8 ≤ x 24 ≤ − 5 12 + 5 8 − 1 24 ≤ x 24 ≤ 5 24 − 1 ≤ x ≤ 5

- 7 8 + 5 6 < x 24 ≤ 5 8 + - 5 12

⇔ - 21 24 + 20 24 ≤ x 24 ≤ 15 24 + - 10 24 ⇔ - 1 24 ≤ x 24 ≤ 5 24

-1 ≤ x ≤ 5 mà x ∈ Z. Do đó: x ∈ { -1 ; 0 ; 1 ; 2 ; 3 ; 4 ; 5 }

`#3107.101107`

a)

\(5\left(x-1\right)^3=40\\\Rightarrow\left(x-1\right)^3=40\div5\\ \Rightarrow\left(x-1\right)^3=8\\ \Rightarrow\left(x-1\right)^3=2^3\\ \Rightarrow x-1=2\\ \Rightarrow x=2+1\\ \Rightarrow x=3\)

Vậy, `x = 3`

b)

\(3^{2x+1}+9^x=324?\\ \Rightarrow3^{2x}\cdot3+3^{2x}=324\\ \Rightarrow3^{2x}\cdot\left(3+1\right)=324\\ \Rightarrow3^{2x}\cdot4=324\\ \Rightarrow3^{2x}=81\\ \Rightarrow3^{2x}=3^4\\ \Rightarrow2x=4\\ \Rightarrow x=2\)

Vậy, `x = 2`

c)

\(5^x-13=3\cdot2^2\\ \Rightarrow5^x-13=12\\ \Rightarrow5^x=12+13\\ \Rightarrow5^x=25\\ \Rightarrow5^x=5^2\\ \Rightarrow x=2\)

Vậy, `x = 2`

d)

\(8^x+2^{3x+1}=192\\ \Rightarrow2^{3x}+2^{3x}\cdot2=192\\ \Rightarrow2^{3x}\left(1+2\right)=192\\ \Rightarrow2^{3x}\cdot3=192\\ \Rightarrow2^{3x}=64\\ \Rightarrow2^{3x}=2^6\\ \Rightarrow3x=6\\ \Rightarrow x=2\)

Vậy, `x = 2.`

-1 ≤ x ≤ 5 mà x ∈ Z. Do đó: x ∈ { -1 ; 0 ; 1 ; 2 ; 3 ; 4 ; 5 }