I am having some difficulties balancing the following equations:

Question

Cr2O3(s)+CO(g)->Cr(s)+CO2

Ca(OH)2(aq)+Na3PO4(aq)->Ca3(PO4)2(s)+NaOH(aq)

Sb2S3(s)+O2(g)->Sb2O3(s)+SO2(g)

Answer 1

Cr2O3(s) + 3CO(g)->2Cr(s) + 3CO2

3Ca(OH)2(aq) + 2Na3PO4(aq) -> Ca3(PO4)2(s) + 6NaOH(aq)