HEHE !! username le sarahi hasayo yaar.. tyasto bacha buchi trick lagayera bho ta la **** both LHS and RHS correspond to (a^2 - 2ab + b^2 = (a-b)^2 ) so, (4-13)^2 = (22-13)^2 Taking square root of both, 4-13 = 22-13 **** yo ta tyaho baccha bucchi lai -1 =+1 prove garera almalyaune trick nai bho ni... When u take square root of something... how can u forget that its always + and -. that proves... 9 =9 and and -9=-9. now can u say -9=+9.???? So Username is also wrong!! hehe.. I am saying u guys .. no point in trying using the existing numbering system... u need to develop new coding system for that..hehe Sarala's answer was also ridiculous.. thanks DWI for clarifying where c was wrong...