Answer:
1) 3|x|=[0; infinity). there is no infinity sign lol
2) 3|x|= (0; infinity)
Mary spent $10.30 on dinner to stay in budget.
Step-by-step explanation:
Amount spent on breakfast = $6.25
Amount spent on lunch = $8.95
Amount spent on dinner = x
Average = $8.50
Average = 

Multiplying both sides by 3

Mary spent $10.30 on dinner to stay in budget.
Keywords: Average, addition
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