:))

\(PTHH:CO_2+Ca\left(OH\right)_2\rightarrow CaCO_3+H_2O\)

\(n_{Ca\left(OH\right)_2}=\dfrac{m}{M}=\dfrac{37}{74}=0,5\left(mol\right)\)

\(Theo.PTHH\Rightarrow n_{CO_2}=n_{CaCO_3}=n_{Ca\left(OH\right)_2}=0,5\left(mol\right)\)

\(m_{CO_2}=n.M=0,5.44=22\left(g\right)\)

nghỉ đi

tắt

\(a,CTHH.chung:Na_x\left(PO_4\right)_y\\ Theo.quy.tắc.hóa.trị:x.I=y.III\\ Chuyển.thành.tỉ.lệ:\dfrac{x}{y}=\dfrac{3}{1}\\ \Rightarrow\left\{{}\begin{matrix}x=3\\y=1\end{matrix}\right.\\ CTHH:Na_3PO_4\)

\(b,CTHH.chung:Ca_x\left(PO_4\right)_y\\ Theo.quy.tắc.hóa.trị:x.II=y.III\\ Chuyển.thành.tỉ.lệ:\dfrac{x}{y}=\dfrac{3}{2}\\ \Rightarrow\left\{{}\begin{matrix}x=3\\y=2\end{matrix}\right.\\ CTHH:Ca_3\left(PO_4\right)_2\)

\(n^4-1\\ =\left(n^2-1\right)\left(n^2+1\right)\\ =\left(n-1\right)\left(n+1\right)\left(n^2+1\right)\)

\(Vì.n\notin B_{\left(2\right)}\)

\(\Rightarrow\left(n-1\right)⋮2\\ \left(n+1\right)⋮2\\ \left(n^2+1\right)⋮2\\ \Rightarrow\left(n-1\right)\left(n+1\right)\left(n^2+1\right)⋮2.2.2=2^3=8\)

\(4x\left(x-3\right)-\left(2x+3\right)\left(2x-3\right)=-3\)

\(4x^2-12x-4x^2+9+3=0\)

\(12-12x=0\\ \Rightarrow1-x=0\\ \Rightarrow x=1\)

Chào Hoàng lâu ko gặp