( 3x - 6 ) . 3 = 18

3x - 6 = 18 : 3 = 6

3x = 6 + 6 = 12

x= 4

6x - 5 = 613

6x = 613 + 5 =618

x=103

x-36:18=12

x - 2 = 12

x= 12 + 2

x= 14

\(\left(3x-6\right).3=18\)

\(\Rightarrow3x-6=19:3=6\)

\(\Rightarrow3x=6+6=12\)

\(\Rightarrow x=12:3=4\)

\(6.x-5=613\)

\(\Rightarrow6x=613+ 5=618\)

\(\Rightarrow x=618:6=103\)

\(x-36:18=12\)

\(\Rightarrow x-2=12\)

\(\Rightarrow x=12+2=14\)

Ủng hộ nha m.n ^_^

\(\left(3x-6\right)\cdot3=18\)

\(\Rightarrow3x-6=18:3=6\)

\(\Rightarrow3x=6+6=12\)

\(\Rightarrow x=12:3=4\)

\(6\cdot x-5=613\)

\(\Rightarrow6\cdot x=613+5=618\)

\(\Rightarrow x=61=618:6=103\)

\(x-36:18=12\)

\(=x-2=12\)

\(\Rightarrow x=12+2=14\)

Ủng hộ mk nka!!!^_^^_^^_^

\(\Leftrightarrow3^{x-1}\left(1+3+3^2\right)=39\\ \Leftrightarrow3^{x-1}\cdot13=39\\ \Leftrightarrow3^{x-1}=3=3^1\\ \Leftrightarrow x-1=1\Leftrightarrow x=2\)

\(\Leftrightarrow3^x\cdot\dfrac{13}{3}=39\)

\(\Leftrightarrow x=2\)

\(3^{x-1}+3^x+3^{x+1}=39\\ \Rightarrow3^x:3+3^x+3^x.3=39\\ \Rightarrow3^x.\dfrac{1}{3}+3^x+3^x.3=39\\ \Rightarrow3^x\left(\dfrac{1}{3}+1+3\right)=39\\ \Rightarrow3^x.\dfrac{13}{3}=39\\ \Rightarrow3^x=9\\ \Rightarrow3^x=3^2\\ \Rightarrow x=2\)

\(\left(x-36\right):18=12\)

\(x-36=12x18\)

\(x-36=216\)

           \(x=216+36\)

           \(x=252\)

\(K\)\(nha!!!\)

x-36:18=12

=>x-2=12

=>x=12+2

=>x=14

Vậy x=14

x-36:18=12

x=12x18

x=216

x=216+36

x=252

nhé

3(x+3)=18+36

3(x+3)=54

x + 3 = 54 : 3

x + 3 = 18

x = 18 - 3

x = 15

3 (x+3)=18+36

3 (x+3)=54

x+3=54÷3

x+3=18

x=18-3

x=15

3(x+3)=18+36

3(x+3)=54

(x+3)=54/3

(x+3)=18

x=18-3

x=15

6(x+85)=36+210

6(x+85)= 246

x + 85 = 246 : 6

x + 85 = 41

x = 41 - 85

x = -44

6(x + 85 ) = 36 + 210 

6(x + 85 ) = 246 

   x + 85   = 246 : 6 

   x + 85   = 41 

         x    =  41 - 85 

         x    =  - 44

6 (x+85)=36+210

6 (x+85)=246

x+85=246÷6

x+85=41 

x=41-85

x=41+(-85)

x=-44

MẤY BẠN CAO ĐIỂM NHỚ NHA

\(\frac{36}{1\cdot3\cdot5}+\frac{36}{3\cdot5\cdot7}+\frac{36}{5\cdot7\cdot9}+...+\frac{36}{25\cdot27\cdot29}\)

\(=9\left[\frac{4}{1\cdot3\cdot5}+\frac{4}{3\cdot5\cdot7}+\frac{4}{5\cdot7\cdot9}+...+\frac{4}{25\cdot27\cdot29}\right]\)

\(=9\left[\frac{1}{1\cdot3}-\frac{1}{3\cdot5}+\frac{1}{3\cdot5}-\frac{1}{5\cdot7}+...+\frac{1}{25\cdot27}-\frac{1}{27\cdot29}\right]\)

\(=9\left[\frac{1}{3}-\frac{1}{783}\right]=9\cdot\frac{260}{783}=\frac{260}{87}\)

Đặt \(A=\frac{36}{1.3.5}+\frac{36}{3.5.7}+\frac{36}{5.7.9}+...+\frac{36}{25.27.29}\)

\(\Rightarrow\frac{1}{9}A=\frac{4}{1.3.5}+\frac{4}{3.5.7}+\frac{4}{5.7.9}+...+\frac{4}{25.27.29}\)

\(\Rightarrow\frac{1}{9}A=\frac{1}{1.3}-\frac{1}{3.5}+\frac{1}{3.5}-\frac{1}{5.7}+...+\frac{1}{25.27}-\frac{1}{27.29}\)

\(\Rightarrow\frac{1}{9}A=\frac{1}{1.3}-\frac{1}{27.29}\)

\(\Rightarrow\frac{1}{9}A=\frac{261}{783}-\frac{1}{783}\)

\(\Rightarrow\frac{1}{9}A=\frac{260}{783}\)

\(\Rightarrow A=\frac{260}{783}\div\frac{1}{9}\)

\(\Rightarrow A=\frac{2340}{783}=\frac{260}{87}\)

3600

3600

3600