Calculating the solubility of calcium carbonate at set pH values

Question

Calculate the solubility of CaCO3 Ksp=3×10^-9 in a buffered solution with a pH=6.82 and 8.98, please? The working behind this would be appreciated.

Answer 1

Here's a link to an explanation. It is somewhat involved and that's with assumptions about the dominant species: https://www.colby.edu/chemistry/CH142/CH142A/SolubilityCalciumCarbonate.pdf