125.5^x + 5^x+1 = 3250

125.5^x + 5^x.5¹ = 3250

5^x(125 + 5¹) = 3250

5^x.130 = 3250

5^x = 3250 : 130

5^x = 25

5^x = 5²

=> x = 2

dề bài có sai không bạn?

5^x + 5^x+2 = 3250

=> 5^x + 5^x.5² = 3250

=> 5^x.(1 + 5²) = 3250

=> 5^x.(1 + 25) = 3250

=> 5^x. 26 = 3250

=> 5^x = 3250 : 26

=> 5^x = 125

=> 5^x = 5³

=> x = 3

Vậy x = 3.

\(5^{x+2}=3250-5^x\)

\(\Rightarrow5^x.5^2+5^x=3250\)

\(\Rightarrow5^x\left(5^2+1\right)=3250\)

\(\Rightarrow5^x.26=3250\)

\(\Rightarrow5^x=125\)

\(\Rightarrow5^x=5^3\)

\(\Rightarrow x=3\)

Vậy x = 3

125 . 5^x + 5^x+1 = 3250

125 . 5^x + 5^x . 5 = 3250

5^x . ( 125 + 5 ) = 3250

5^x . 130 = 3250

5^x = 3250 : 130

5^x = 25

5^x = 5²

=> x = 2

a.\(\left(3x-2\right)^2=16\)

Ta có: \(\left(3x-2\right)^2=16\)

\(\Rightarrow\left(3x-2\right)^2=\left(4\right)^2\)

\(\Rightarrow3x-2=4\)

\(\Rightarrow3x=6\)

\(\Rightarrow x=2\)

b. \(\left(\dfrac{4}{5}x-\dfrac{3}{4}\right)^3=\dfrac{-8}{125}\)

\(\Rightarrow\left(\dfrac{4}{5}x-\dfrac{3}{4}\right)^3=\left(\dfrac{-2}{5}\right)^3\)

\(\Rightarrow\dfrac{4}{5}x-\dfrac{3}{4}=\dfrac{-2}{5}^{ }\)

\(\Rightarrow\dfrac{4}{5}x-=\dfrac{7}{20}\)

\(\Rightarrow x=\dfrac{7}{16}\)

c. \(5^{x+2}+5^x=3250\)

\(5^x.5^2+5^x=3250\)

\(5^x.\left(5^2+1\right)=3250\)

\(5^x.26=3250\)

\(5^x=125\)

\(5^x=5^3\)

\(x=5\)

   ( 3250 : 100) x 5

= 32,5 x 5

= 162,5

cách 2:  ( 3250 :  100) x 5

   = 3250 x 5 : 100

  = 16250 : 100

= 162,5 

=650:100=6,5

(3250:100)x5

=32,5x5

=162,5

\(1.=5^x\left(1+5^2\right)=5^x.26=3250\)

\(< =>5^x=125=>x=3\)

2. Để P có giá trị lớn nhất thì -/x-3/ có giá trị bé nhất...

=> x-3 có bé nhất hay x=3;

=>ĐPCM