2 - [ 8又1/4 - ( 17 - 8*1又7/8 ) ] / 0.25
= 2 - [ 8又1/4 - 17 + 8*(1 + 7/8 ) ] ÷ (1/4)
= 2 - [ 8又1/4 - 17 + 8 + 7 ] × 4
= 2 - [ 8又1/4 - 2 ]×4
= 2 - (6又1/4 ×4)
= 2 - ( 6+ 1/4) ×4
= 2 - (24 + 1)
= - 23
2 - [ 8又1/4 - ( 17 - 8*1又7/8 ) ] / 0.25
= 2 - [ 8又1/4 - 17 + 8*(1 + 7/8 ) ] ÷ (1/4)
= 2 - [ 8又1/4 - 17 + 8 + 7 ] × 4
= 2 - [ 8又1/4 - 2 ]×4
= 2 - (6又1/4 ×4)
= 2 - ( 6+ 1/4) ×4
= 2 - (24 + 1)
= - 23