The balance equation will be
3Ca(OH)2+ 2H3PO4--->Ca3(PO4)2 + 6H2O
Explanation;
The balance equation show that 3 mole of calcium hydroxide reacts with 2moles of phosphoric acid produces 1 mole of tricalcium phosphate and 6 mole of water..
Equation given is question is unbalanced
Product shows 3 Ca ions to get the same atom in reactant; multiply Ca(OH) with 3
And to get 2 phosphate ions we have to multiply phosphoric acid with 2
Now balance the number of Oxygen and hydrogen.multiply the water with 6