What is the diameter in inches of a circle that has an area of 81

What is the difference between the predicted value and the actual value

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"

Kayla made observations about the sellin price of a new brand of coffee that sold in the three different sized bags she recorded those observations in the following table 6 is $2.10 8 is $2.80 and 16 is to $5.60 use the relationship to predict the cost of a 20oz bag of coffee.