1) Yes, I do.

2) I think domestic charity is more important.

3) That amount will help poor children, homeless people who need help.

4) Yes, I think children should do so

\(3^{x+4}+3^x=2214\Rightarrow3^x.81+3^x=2214\Rightarrow3^x.\left(81+1\right)=2214\Rightarrow3^x.82=2214\Rightarrow3^x=27=3^3\Rightarrow x=3\)

a) \(\left(x-\dfrac{1}{4}\right)^2=0\Rightarrow x-\dfrac{1}{4}=0\Rightarrow x=\dfrac{1}{4}\)

b) \(\left(x+\dfrac{1}{3}\right)^2=4\Rightarrow\left[{}\begin{matrix}x+\dfrac{1}{3}=2\\x+\dfrac{1}{3}=-2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{5}{3}\\x=-\dfrac{7}{3}\end{matrix}\right.\)
 

becase ⇒ because

gà mái

\(4x^2+4x+1=\left(2x\right)^2+2.2x.1+1^2=\left(2x+1\right)^2=0\Rightarrow2x+1=0\Rightarrow2x=-1\Rightarrow x=-\dfrac{1}{2}\)

\(100\div55=1\) (dư 45)

\(\left(2x+1\right)^2=9\Leftrightarrow\left[{}\begin{matrix}2x+1=3\\2x+1=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=2\\2x=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-2\end{matrix}\right.\)

\(x^2+4x+4=x^2+2.2.x+2^2=\left(x+2\right)^2=0\Rightarrow x+2=0\Rightarrow x=-2\)

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