-1/2-26/5-1+15/3-4.5+7/3
= -0.5-26/5-1+5-4.5+7/3
= -0.5-4.5 -1+5+(7/3-26/5)
= -6 -1 +5 + (35- 78 )/15
= -2 - 43/15
= -(30 + 43)/15
=- 15分之 73