[- 5 / 4] / 0.25 / [- 15 / 4] [- 2 / 5] square / [- 12 / 5] - 8 / 21 * [- 7 / 4] - 0.25

[- 5 / 4] / 0.25 / [- 15 / 4] [- 2 / 5] square / [- 12 / 5] - 8 / 21 * [- 7 / 4] - 0.25

[- 5 / 4] / 0.25 / [- 15 / 4]
=5/4*4/1*4/15
=4/3
[- 2 / 5] square / [- 12 / 5] - 8 / 21 * [- 7 / 4] - 0.25
=4/25*(-5/12)+8/21*7/4-1/4
=-1/15+4/3-1/4
=(-4+80-15)/60
=61/60