205×205/102
=205 X (204 + 1)/102
=205 X (204/102 + 1/102)
=205 X(2 + 1/102)
=205 X 2 + 205/102
=410 + (204 + 1)/102
=410 +(204/102 + 1/102)
=410 + 2 +1/102
=412又1/102
205×205/102
=205 X (204 + 1)/102
=205 X (204/102 + 1/102)
=205 X(2 + 1/102)
=205 X 2 + 205/102
=410 + (204 + 1)/102
=410 +(204/102 + 1/102)
=410 + 2 +1/102
=412又1/102