\(c,CTTQ:Al_x^{III}(OH)_y^{I}\\ \Rightarrow x.III=y.I\Rightarrow \dfrac{x}{y}=\dfrac{1}{3}\Rightarrow x=1;y=3\\ \Rightarrow CTHH:Al(OH)_3\\ d,CTTQ:Ca_x^{II}(PO_4)_y^{III}\\ \Rightarrow x.II=y.III\Rightarrow \dfrac{x}{y}=\dfrac{3}{2}\Rightarrow x=3;y=2\\ \Rightarrow CTHH:Ca_3(PO_4)_2\)
\(Al+3OH->Al\left(OH\right)_3\)
CTHH: AlxOHy
\(\dfrac{x}{y}=\dfrac{I}{III}=\dfrac{1}{3}\)
=> CTHH: AlOH3
CTHH: CaxPO4y
\(\dfrac{x}{y}=\dfrac{III}{II}=\dfrac{3}{2}\)
=> CTHH: Ca3(PO4)3