Answer:
10
Step-by-step explanation:
Answer/Step-by-step explanation:
1.a)(iv). 
Positive multiplied by negative = negative


2a.) 73.48 +(-37.3)

73.48 - 37.3 = 36.18
3c.)
÷
Convert to proper fraction
÷
Change ÷ to × and flip the fraction on your right upside down

3d.) -52.25 ÷ (-5.5) = 
(Note: - ÷ - = + )

Answer:
x=12
Step-by-step explanation:
I've included a photo of the solution here.
Total portions are
5+4+3
12
One portion,
4860 / 12
405
So
5 : 4 : 3
5*405 : 4*405 : 3:405
2025 : 1620 : 1215