1.2乘(-2又五分之三)乘(-2.5)乘(-三分之五)
=1.2 ×(-2-3/5) × (-2.5) ×(-5/3)
= - 1.2 × 2.6 × 2.5 × 5/3
= - 7.8 × 5/3
= - 2.6 ×5
= -13