Question

Tìm x : (x + 3)^2x+1 = (x + 3)^2x+3

Answer 1

=> (x+3)^2x.(x+3)= (x+3)^2x.(x+3)³

=> (x+3)^2x= (x+3)^2x.(x+3)³:(x+3)

=> (x+3)^2x.1= (x+3)^2x. (x+3)²

=> 1=(x+3)²\(\Rightarrow\orbr{\begin{cases}\left(x+3\right)^2=1^2\\\left(x+3\right)^2=\left(-1\right)^2\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x+3=1\\x+3=\left(-1\right)\end{cases}}\Rightarrow\orbr{\begin{cases}x=\left(-2\right)\\x=\left(-4\right)\end{cases}}\)

\(\Rightarrow x=\left\{-2;-4\right\}\)

Answer 2

\(\Rightarrow\left(x+3\right)^{2x+1}-\left(x+3\right)^{2x+3}=0\)

\(\Rightarrow2x+1-2x+3=0\)

Mik quên cah làm rùi

Answer 3

đứa icewing gì đó làm sai rùi kết quả ra -2 mà

Answer 4

CMR : 1/7² - 1/7⁴ + ... + 1/7^4n-1 - 1/7⁴ⁿ + ... + 1/7⁹⁸ - 1/7¹⁰⁰  < 1/50

Giúp mình với, mình cảm ơn.

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