\(8^2.32^4=2^{2.3}.2^{5.4}=2^6.2^{20}=2^{26}\)

\(64^3.256^2=2^{6.3}.2^{8.2}=2^{18}.2^{16}=2^{34}\)

câu 3; 67108864    

caau4:

2^x = 4 . 128 = 512

2^x = 2^9

=> x = 9

  b) 2^x . 3^x = 4.9

=> 2^x . 3^x = 36

=> x = 2

2\(^x\)=4.128

2\(^x\)=512

2\(^x\)=2\(^9\)

=> x=9

đúng nha

x+x+x+82=-2-x

=>x+x+x+x=-2-82

4x=-84

x-84/4

x=-21

(a-b+c-d)-9a+b+c+d)=a-b+c-d-a-b-c-d

=(a-a)-(b+b)+(c-c)-(d-d)

=0-2b+0-2d

=-2b-2d

(-a+b-c)+(a-b)-(a-b+c)

=-a+b-c+a-b-a+b-c

=(-a+a-a)+(b-b+b)-(c+c)

=-a+b-2c

-(a-b-c)+(b-c+d)-(a+b+d)

=-a+b+c+c-c+d-a-b-d

=(-a-a)+(b-b)+(c+c-c)+(d-d)

=-2a+0+c+0

=-2a+c

x+x+x+82=-2-x

      3x+82=-2-x     

       3x+x=-2-82

           4x=-84

   x=-84:4=-21

5.(-40).x=-100

   -200.x=-100

          x=-100:(-200)

          x=0,5

-1.(-3).(-6).x=36

          -18.x=36

                x=36:(-18)

                x=-2

|1-4x|=7

Xảy ra hai trường hợp:1-4x=7=>4x=1-7=-6=>x=-6:4=-1,5

                                    1-4x=-7=>4x=1+7=8=>x=8:4=2

Vì x là số nguyên nên ta chỉ có một đáp án đó là:2

x.(x-2)=0+> x=0 hoặc  x=2

x.(x-2)>0=>x=-1;-2;-3;-4;...

\(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+..+\frac{1}{x\left(x+2\right)}=\frac{20}{41}\)

\(\frac{1}{2}\left(\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{x.\left(x+2\right)}\right)=\frac{20}{41}\)

\(\frac{1}{2}\left(\frac{3-1}{1.3}+\frac{5-3}{3.5}+\frac{7-5}{5.7}+...+\frac{\left(x+2\right)-x}{x\left(x+2\right)}\right)=\frac{20}{41}\)

\(\frac{1}{2}\left(1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{x}-\frac{1}{x+2}\right)=\frac{20}{41}\)

\(\frac{1}{2}\left(1-\frac{1}{x+2}\right)=\frac{20}{41}\)

\(1-\frac{1}{x+2}=\frac{20}{41}:\frac{1}{2}\)

\(1-\frac{1}{x+2}=\frac{40}{41}\)

\(\frac{1}{x+2}=1-\frac{40}{41}\)

\(\frac{1}{x+2}=\frac{1}{41}\)

\(x+2=41\)

\(x=41-2\)

\(x=39\)

Tìm x 

a) \(\frac{1}{1\times3}+\frac{1}{3\times5}+\frac{1}{5\times7}+...+\frac{1}{x\times\left(x+2\right)}=\frac{20}{41}\)

\(\Rightarrow\frac{1}{2}\times\left(\frac{2}{1\times3}+\frac{2}{3\times5}+\frac{2}{5\times7}+...+\frac{2}{x\times\left(x+1\right)}\right)=\frac{20}{41}\)

\(\Rightarrow\frac{2}{1\times3}+\frac{2}{3\times5}+\frac{2}{5\times7}+...+\frac{2}{x\times\left(x+2\right)}=\frac{20}{41}:\frac{1}{2}\)

\(\Rightarrow\frac{2}{1\times3}+\frac{2}{3\times5}+\frac{2}{5\times7}+...+\frac{2}{x\times\left(x+2\right)}=\frac{40}{41}\)

\(\Rightarrow1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{x}-\frac{1}{\left(x+2\right)}=\frac{40}{41}\)

\(\Rightarrow1-\frac{1}{x+2}=\frac{40}{41}\)

\(\Rightarrow\frac{1}{x+2}=1-\frac{40}{41}\)

\(\Rightarrow\frac{1}{x+2}=\frac{1}{41}\)

\(\Rightarrow x+2=41\)

\(\Rightarrow x=41-2\)

\(\Rightarrow x=39\)

Vậy x = 39