3x²-51 = 24

=>3x²=75

=>x²=25

=> x = + - 5

(5x+1)²=36/49

(5x+1)²=\(\left(\frac{6}{7}\right)^2\)

5x+1=6/7

5x=-1/7

x=-1/35

5^x=125

5^x=5³

^x=3

(3x-2)⁵=-243

(3x-2)⁵=(-3)⁵

3x-2=-3

3x=-1

x=-1/3

\(\left(3x^2-51\right)^{2n}=\left(-24\right)^{2n}\)

\(3x^2-51=-24\)

\(3x^2=27\)

\(x^2=9\)

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

TH1: x=3

TH2: x=-3

=.= hok tốt!!

Thanks miyano shiho nhiều lắm lắm lun!!

a) x = 1

b) x = -1

a) x²-2x=-1

<=> x²-2x+1=0

<=> (x - 1)² = 0
=> x = 1

\(\left(3x^2-51\right)^{2n}=\left(-24\right)^{2n}\)

\(\Leftrightarrow3x^2-51=-24\)

\(\Leftrightarrow3x^2=27\)

\(\Leftrightarrow x^2=9\)

\(\Leftrightarrow x=\pm3\)

(3x² - 51)²ⁿ = (-24)²ⁿ

=> \(\orbr{\begin{cases}3x^2-51=-24\\3x^2-51=24\end{cases}=>\orbr{\begin{cases}3x^2=27\\3x^2=75\end{cases}}}\) 

=>\(\orbr{\begin{cases}x^2=9\\x^2=25\end{cases}=>}\orbr{\begin{cases}x=3\\x=5\end{cases}}\)

a)  3n = 35 => n = 5

b) 2n = 28 => n = 8

--thodagbun--

( h tớ lm b đt nè :( )

Chc câu lm nhanh nên v

(3x² - 51)²ⁿ = 576ⁿ

=> (3x² - 51)²ⁿ = 24²ⁿ = (-24)²ⁿ

\(\Rightarrow\left[\begin{array}{nghiempt}3x^2-51=24\\3x^2-51=-24\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}3x^2=75\\3x^2=27\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}x^2=25\\x^2=9\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}\left[\begin{array}{nghiempt}x=5\\x=-5\end{array}\right.\\\left[\begin{array}{nghiempt}x=3\\x=-3\end{array}\right.\end{array}\right.\)

Vậy \(\left[\begin{array}{nghiempt}x=5\\x=-5\\x=3\\x=-3\end{array}\right.\)

cảm ơn bạn nhiều, nhờ bạn giúp mình vào các bài tập sau