Could some one answers thies questions for me

______Ag + ______S8______Ag2S
______Pb + ______H3PO4______H2 + ______Pb3(PO4)2
______CH4______C + ______H2
______Ca(OH) 2 + ______H3PO4______Ca3(PO4)2 + ______H2O
And their reactions?

16Ag + S8 -------------> 8Ag2S combination reaction

3Pb + 2H3PO4 ------------->3H2 + Pb3(PO4)2 single replacement reaction

CH4 ------------------------------> C+ 2H2 decomposition reaction

3Ca(OH)2 + 2H3PO4 -----------> Ca3(PO4)2 + 6H2O double replacement reaction