<prompt> Acha a_1, a_2, dots, a_4001 iwe mfuatano wa hesabu kiasi kwamba a_1 a_4001 50 nafrac1a_1 a_2 frac1a_2 a_3 vitone frac1a_4000 a_4001 10.Tafuta a_1 - a_4001.  <response>: Acha d iwe tofauti ya kawaida. Kishaanzaalignfrac1a_n a_n 1 frac1a_n a_n d frac1d cdot fracda_n a_n d frac1d cdot fraca_n d - a_na_n a_n d frac1d kushoto frac1a_n - frac1a_n d kulia frac1d kushoto frac1a_n - frac1a_n 1 kulia.mwishoalignHivyo,anzaalignfrac1a_1 a_2 frac1a_2 a_3 vidoti frac1a_4000 a_4001 frac1d kushoto frac1a_1 - frac1a_2 kulia frac1d kushoto frac1a_2 - frac1a_3 kulia vitone frac1d kushoto frac1a_4000 - frac1a_4001 kulia frac1d kushoto frac1a_1 - frac1a_4001 kulia frac1d cdot fraca_4001 - a_1a_1 a_4001.endalignKwa kuwa tuna mfuatano wa hesabu, a_4001 - a_1 4000d, hivyofrac1d cdot fraca_4001 - a_1a_1 a_4001 frac4000a_1 a_4001 10.Kwa hiyo, a_1 a_4001 frac400010 400.Kishaa_1 - a_40012 a_12 - 2a_1 a_4001 a_40012 a_1 a_40012 - 4a_1 a_4001 502 - 4 cdot 400 900,hivyo a_1 - a_4001 30. 