288:(x-3)²=2

=> (x-3)²=144

=>x-3=12(vì x thuộc N)

=> x=15

\(8.6+288:\left(x-3\right)^2=50\)

\(\Rightarrow48+288:\left(x-3\right)^2=50\)

\(\Rightarrow288:\left(x-3\right)^2=50-48=2\)

\(\Rightarrow\left(x-3\right)^2=288:2=144\)

Mà \(\left(x-3\right)^2=144=12^2\)

\(\Rightarrow x-3=12\)

\(\Rightarrow x=12+3\)

\(\Rightarrow x=15\)

8.6+288:(x-3)²=50

48+288:(x-3)²=50

288:(x-3)²=50-48

288:(x-3)²=2

(x-3)²=288:2

(x-3)²=144

=>(x-3)²=12²=(-12)²

=>\(\orbr{\begin{cases}x-3=12\\x-3=-12\end{cases}}\)

=>\(\hept{\orbr{\begin{cases}x=15\\x=\left(-9\right)\end{cases}}}\)

\(8\cdot6+288:\left(x-3\right)^2=50\)

\(48+288:\left(x-3\right)^2=50\)

\(288:\left(x-3\right)^2=50-48=2\)

\(\left(x-3\right)^2=288:2=144\)

Vì x là số tự nhiên nên (x-3) là số tự nhiên.

\(\left(x-3\right)^2=12^2\)

\(x-3=12\)

\(x=12+3=15\)

\(\left(18,6.\frac{16x-3}{2}+\frac{139,5-238,25x}{5}\right):\left(1+8+15+...+281+288\right)=\frac{1}{3}\)

\(\Rightarrow\left(\frac{297,6x-55,8}{2}+\frac{139,5-238,25x}{5}\right):\left(\frac{\left(288+1\right).\left[\left(288-1\right):\left(8-1\right)+1\right]}{2}\right)=\frac{1}{3}\)

\(\Rightarrow\left(\frac{1488x-279}{10}+\frac{279-476,5x}{10}\right):6069=\frac{1}{3}\)

\(\Rightarrow\frac{1488x-279+279-476,5x}{10}=2023\)

\(\Rightarrow1488x-476,5x=20230\)

\(\Rightarrow1011,5x=20230\)

\(\Rightarrow x=20\)

             Bài làm :

Ta có :

\(\left(18,6.\frac{16x-3}{2}+\frac{139,5-238,25x}{5}\right)\div\left(1+8+15+...+281+288\right)=\frac{1}{3}\)

\(\Leftrightarrow\left(\frac{297,6x-55,8}{2}+\frac{139,5-238,25x}{5}\right)\div\left(\frac{\left(288+1\right).\left[\left(288-1\right):\left(8-1\right)+1\right]}{2}\right)=\frac{1}{3}\)

\(\Leftrightarrow\left(\frac{1488x-279}{10}+\frac{279-476,5x}{10}\right)\div6069=\frac{1}{3}\)

\(\Leftrightarrow\frac{1488x-279+279-476,5x}{10}=2023\)

\(\Leftrightarrow1488x-476,5x=20230\)

\(\Leftrightarrow1011,5x=20230\)

\(\Leftrightarrow x=20\)

Vậy x=20

( 1/1.2 + 1/2.3 + 1/3.4 + 1/4.5 +1/5.6 ) x 10 - x = 0

= ( 1- 1/2 +1/2 -1/3 +1/3 - 1/4 + 1/4 - 1/5 +1/5 -1/6 ) x 10 - x = 0

= ( 1 - 1/6 ) x 10 - x = 0

= 5/6 x 10 - x =0

=   25/3 - x =0

               x = 25/3 - 0

                x  = 25/3

\(\left(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+\frac{1}{4\times5}+\frac{1}{5\times6}\right)\times10-x=0\)

\(\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}\right)\times10-x=0\)

\(\left(\frac{1}{1}-\frac{1}{6}\right)\times10-x=0\)

\(\frac{5}{6}\times10-x=0\)

\(\frac{25}{3}-x=0\)

x              =\(\frac{25}{3}-0=\frac{25}{3}\)

a) \(5\times\left(3+7\times x\right)=400\)

\(3+7\times x=80\)

\(7\times x=77\)

\(x=11\)

b) \(x\times37+x\times63=1200\)

\(x\times\left(37+63\right)=1200\)

\(x\times100=1200\)

\(x=12\)

c) \(x\times6+12:3=40\)

\(x\times6+4=40\)

\(x\times6=36\)

\(x=6\)

d) \(4+6\times\left(x+1\right)=70\)

\(6\times\left(x+1\right)=66\)

\(x+1=11\)

\(x=10\)

e) \(163:x+34:x=10\)

\(\left(163+34\right):x=10\)

\(197:x=10\)

\(x=19,7\)

Ta có : 8 . 6 + 288 : (x - 3)² = 50

=> 48 + 288 : (x - 3)² = 50

=> 288 : (x - 3)² = 50 - 48

=> 288 : (x - 3)² = 2

=> (x - 3)² = 288 : 2

=> (x - 3)² = 144

=> không tìm được x thỏa mãn điều kiện trên

8.6+288:(x-3)² = 50

<=> 48+288:(x-3)² = 50

<=> 288:(x-3)² = 50-48 = 2

<=> (x-3)² = 2.288 = 576 = 24²

<=> \(\orbr{\begin{cases}x-3=24\\x-3=-24\end{cases}}\)

<=> \(\orbr{\begin{cases}x=24+3=27\\x=3-24=-21\end{cases}}\)

Vậy x thuộc { 27 ; -21 }

\(8\cdot6+288:\left(x-3\right)^2=50\)

\(48+288:\left(x-3\right)^2=50\)

\(288:\left(x-3\right)^2=50-48\)

\(288:\left(x-3\right)^2=2\)

\(\left(x-3\right)^2=288:2\)

\(\left(x-3\right)^2=144\)

\(Th1:x-3=12\)\(Th2:x-3=-12\)

\(x=12+3=15\)\(x=-12+3=-9\)

Vậy \(x=15\)hoặc \(x=-9\)

a: =>x-3/4=1/6-1/2=1/6-3/6=-2/6=-1/3

=>x=-1/3+3/4=-4/12+9/12=5/12

b: =>x(1/2-5/6)=7/2

=>-1/3x=7/2

hay x=-21/2

c: (4-x)(3x+5)=0

=>4-x=0 hoặc 3x+5=0

=>x=4 hoặc x=-5/3

d: x/16=50/32

=>x/16=25/16

hay x=25

e: =>2x-3=-1/4-3/2=-1/4-6/4=-7/4

=>2x=-7/4+3=5/4

hay x=5/8