\(720:\left(x\times2+x\times3\right)=2\times3\)

\(720:\left(x\times5\right)=6\)

\(x\times5=720:6\)

\(x\times5=120\)

\(x=120:5\)

\(x=24\)

720 :[x +2 . x +3] =2.3

720:(x+2.x+3)=6

x+2.x+3=120

x.(2+3)=120

x.5=120

x=24

\(720:\left[X+2xX+3\right]=2x3\)

\(720:\left[x+\left(2+3\right)\right]=6\)

          \(x+5=720:6\)

           \(x+5=120\)

           \(x=120-5\)

           \(x=115\)

\(720\div\left(x\times5\right)=6\)

\(x\times5=720\div6\)

\(x\times5=120\)

\(x=120\div5\)

\(x=24\)

#TThuHuongg

\(3^{x+1}+3^{x+2}=2^2.3^4\)

\(3^{x+1}+3.3^{x+1}=4.81\)

\(4.3^{x+1}=4.81\)

\(3^{x+1}=81=3^4\)

\(x+1=4\Rightarrow x=3\)

\(x\cdot2+x\cdot3=720:6\)

\(x\cdot\left(2+3\right)=120\)

\(x=120:5\)

\(x=24\)

Dấu " . " là dấu nhân

Học tốt nhé :)

720:(Xx2+Xx3)=6

       Xx2+Xx3=720:6

       Xx2+Xx3=120

      Xx(2+3)   =120 

      Xx5          =120

      X              =120:5

      X              =24

Tìm x : 

720 : ( x × 2 + x × 3 ) = 2 × 3

720 : [ x × ( 2 + 3 ) ]  = 6 

720 : ( x × 5 ) = 6 

x × 5 = 720 : 6 

x × 5 = 120 

x = 120 : 5 

x = 24 

Vậy x =24

\(a,x\left(x+5\right)-\left(x-2\right)\left(x+3\right)=0\\ \Leftrightarrow x^2+5x-x^2-x+6=0\Leftrightarrow4x=-6\\ \Leftrightarrow x=-\dfrac{3}{2}\)

\(b,2x^3-18x=0\\ \Leftrightarrow2x\left(x^2-9\right)=0\\ \Leftrightarrow2x\left(x-3\right)\left(x+3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=3\\x=-3\end{matrix}\right.\)

a: Ta có: \(x\left(x+5\right)-\left(x-2\right)\left(x+3\right)=0\)

\(\Leftrightarrow x^2+5x-x^2-3x+2x+6=0\)

\(\Leftrightarrow7x=-6\)

hay \(x=-\dfrac{6}{7}\)

b: Ta có: \(2x^3-18x=0\)

\(\Leftrightarrow2x\left(x-3\right)\left(x+3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=3\\x=-3\end{matrix}\right.\)

Tách ra, dài quá mn đọc là mất hứng làm đó.