1. \(x-8+32=68\)

\(x-8=68-32\)

\(x-8=36\)

\(x=36+8\)

\(x=44\)

_____

2. \(x+8+32=68\)

\(x+8=68-32\)

\(x+8=36\)

\(x=36-8\)

\(x=28\)

_____

3. \(98-x+34=43\)

\(98-x=43-34\)

\(98-x=9\)

\(x=98-9\)

\(x=89\)

_____

4. \(98+x-34=43\)

\(98+x=43+34\)

\(98+x=77\)

\(x=77-98\)

\(x=-21\)

_____

5. \(x:5:4=800\)

\(x:5=800.4\)

\(x:5=3200\)

\(x=3200.5\)

\(x=16000\)

_____

6. \(18+x=384:8\)

\(18+x=48\)

\(x=48-18\)

\(x=30\)

_____

7. \(\left(84,6-2\times x\right):3,02=5,1\)

\(84,6-2.x=5,1.3,02\)

\(84,6-2.x=15,402\)

\(2.x=84,6-15,402\)

\(2.x=69,198\)

\(x=69,198:2\)

\(x=34,599\)

_____

8. \(x\times5=120:6\)

\(x.5=20\)

\(x=20:5\)

\(x=4\)

_____

9. \(\left(15\times24-x\right):0,25=100:0,25\)

\(\left(15.24-x\right):0,25=400\)

\(15.24-x=400.0,25\)

\(15.24-x=100\)

\(360-x=100\)

\(x=360-100\)

\(x=260\)

1,x-8+32=68

=>x-8=68-32=36

=>x=36+8=42

2,x+8+32=68

=>x+8=68-32=36

=>x=36-8=28

3,98-x+34=43

=>98-x=43-34=9

=>x=98-9=89

4,98+x-34=43

=>98+x=43+34=77

=>x=77-98=-21

5,x:5:4=800

=>x:20=800

=>x=800x20=16000

6,18+x=384:8=48

=>x=48-18=30

7,(84,6-2x):3,02=5,1

=>84,6-2x=5,1x3,02=15,402

=>2x=84,6-15,402=69,198

=>x=69,198:2=34,599

8,5x=120:6=20

=>x=20:5=4

9,(15x24-x):0,25=100:0,25=400

=>360-x=400x0,25=100

=>x=360-100=260.

1. \(...\Rightarrow x+24=68\Rightarrow x=68-24=44\)

2. \(...\Rightarrow x+40=68\Rightarrow x=68-40=28\)

3. \(...\Rightarrow3^{2\left(8+x\right)}=9=3^2\Rightarrow2\left(8+x\right)=2\Rightarrow8+x=1\Rightarrow x=-7\)

4. \(...\Rightarrow3^{2\left(8+x\right)}=77\) (bạn xem lại đề)

5. \(...\Rightarrow x:5=800.4\Rightarrow x:5=3200\Rightarrow x=3200.5=16000\)

6. \(...\Rightarrow18+x=48\Rightarrow x=48-18=30\)

7. \(...\Rightarrow84,6-2x=5,1.3,02=15,402\Rightarrow2x=84,6-15,402\Rightarrow2x=69,198\Rightarrow x=34,599\)

8. \(...\Rightarrow5.x=20\Rightarrow x=20:5=4\)

9. \(\left(360-x\right):0,25=400\Rightarrow360-x=400.0,25=100\Rightarrow x=400-100=300\)

<(x-1)(x+1)(x+3)(x+5)-384=0

​<=>(x-1)(x+5)(x+1)(x+3)-384=0

​<=>(x²​+4x-5)(x²+4x+3)-384=0

​đặt y=x^​2​+4x-5 ta được:

​y(y+8)-384=0

<=>y²+8y-384=0

​<=>y²-16y+24y-384=0

​<=>y(y-16)+24(y-16)=0

​<=>(y-16)(y+24)=0

​<=>y-16=0 hoặc y+24 =0

​<=>y=16 hoặc y=-24

​ thay y=x²​+4x-5 ta được

x²​+4x-5=16 hoặc x²​+4x-5=-24

​<=>x²​+4x-21=0 hoặc x²​+4x+19=0

​mà x²+4x+19=x²+4x+4+15=(x+2)²+15>0

​loại x²​+4x+19=0

​=>x^​2​+4x-21=0

​<=>x²+7x-3x-21=0

​<=>x(x+7)-3(x+7)=0

​<=>(x+7)(x-3)=0

​<=>x=-7 hoặc x=3

​vậy S={-7;3}

​

​

​

Số các số là:

              (47-3):4+1=12

x là:

            384:12-1=...

cam on ban

a: \(\Leftrightarrow2^x\cdot2\cdot2^{-2}\cdot5=384\)

\(\Leftrightarrow2^x\cdot\dfrac{5}{2}=384\)

\(\Leftrightarrow2^x=153,6\)(vô lý)

b: Sửa đề:\(3^{x+2}\cdot5^y=45^x\)

\(\Leftrightarrow3^{x+2}\cdot5^y=3^{2x}\cdot5^x\)

=>x=y và 2x=x+2

=>x=y=2

xin lỗi các bạn là toán lớp 7 nha mình chân thành xin lỗi

a: =>(x-5)^3+1/16=31/64

=>(x-5)^3=31/64-4/64=27/64

=>x-5=3/4

=>x=5,75

b: =>x-2,5=2/3 hoặc x-5/2=-2/3

=>x=19/6 hoặc x=11/6

c: =>\(5\cdot2^x-2^x=384\)

=>2^x*4=384

=>2^x=96

hay \(x\in\varnothing\)

d: =>x+2=4

=>x=2

a, đầu bài sai hay sao đó bn

b,\(\dfrac{2}{3}\).3^x+1 - 7.3^x = -405

3^x(\(\dfrac{2}{3}\).3 - 7) = -405

3^x . (-5) = -405

3^x = 81 mà 81 = 3⁴ suy ra x = 4

Câu x ) là bằng - 5 nhé mấy bạn. Làm giúp mình tất cả nhé ! Mình cảm ơn nhiều lắm !

sai đề rồi bạn ơi

a/ \(\frac{2}{3}.3^{x+1}-7.3^x=405\)

<=> 2.3^x-7.3^x=-405

<=> 5.3^x=405

<=> 3^x=81 = 3⁴

=> x=4

b/ (0,4x-1,3)²=5,29=(2,3)²

=> \(\hept{\begin{cases}0,4x-1,3=2,3\\0,4x-1,3=-2,3\end{cases}}\)=> \(\hept{\begin{cases}x=9\\x=-\frac{5}{2}\end{cases}}\)

c/ 5.2^x+1.2^-2-2^x=384

<=> 5.2^x-1-2.2^x-1=384

<=> 3.2^x-1=384

<=> 2^x-1=128=2⁷

=> x-1=7 => x=8

d/ 3^x+2.5^y=45^x

<=> 3^x+2.5^y=3^2x.5^x

=> \(\hept{\begin{cases}x+2=2x\\x=y\end{cases}}\)=> x=y=2