The amount each person brought to the fair x is $ 10
4(0.5 x - $ 3) = $ 8
2 x - $ 12 = $ 8
2x = $ 20
x = $ 10
How to fill the blanks
The blanks are filled using the information from the word problem
The equation is written and solved as follows
4(0.5 x - $ 3) = $ 8
2 x - $ 12 = $ 8
2x = $ 8 + $ 12
2x = $ 20
x = $ 10