if 2+9=711 then find 12+3=??? number Puzzle with answer

Answer: 915

Explanation: if you look at the question we have equations as 2+9=711 14+6=820; 17+11=628 then 12+3=?? from Equation 1 2+9=711 2+9=(2-9)(2+9) = 711 here we used a formula called a+b=(a-b)(a+b) similarly for remaining equations Equation:2 14+6=(14-6)(14+6)=820 Equation:3 17+11=(17-11)(17+11)=628 now we have 12+3=?? 12+3=(12-3)(12+3)=915 12+3=915 is the correct answer