계산: 19492 - 19502 + 19512 - 19522 +...+ 19972 - 1992 + 1992 =...

계산: 19492 - 19502 + 19512 - 19522 +...+ 19972 - 1992 + 1992 =...

19492 - 19502 + 19512 - 19522 +...+ 19972 - 19982 = (1949 + 1950) + (1959 - 1950) + (1951 + 1952) (1951 - 1952) +...+ (1997 + 1998) (1997 - 1998) + 1992 = - (1949 + 1950 + 1951 + 1952 +...+ 1997 + 1998) + 1992 = - (1949 + 1998) × (1998 − 1949 + 1) 2 + 1992 = - 3947 × 502 + 1992 = - 98675 + 3897326 = 7893327. 그러므로 답 은: 7893327.