Answer:
3.6h - 3.1d + 13
Step-by-step explanation:
Combine like terms. Like terms have same variables.
Like terms : (i) 6h and (-2.4h) (ii) -8.1d and 5d
6h + (-8.1d) - 13 + 5d - 2.4h = 6h - 2.4h + (-8.1d) + 5d - 13
= (6 - 2.4)h + (-8.1 + 5)d - 13
= 3.6h - 3.1d + 13