An equation is formed of two equal expressions. The constant of proportionality between the number of cups of coffee and the total bill amount is 2.50.
An equation is formed when two equal expressions are equated together with the help of an equal sign '='.
Given that a cup of coffee cost $2.50. Now, if the total cost of coffees is $22.50, then the number of cups of coffee that was purchased is,
Number of cups of coffee = Total bill amount / Cost of a coffee
Number of cups of coffee = $22.50 / $2..50
Number of cups of coffee = 9
A.) An equation for the total bill amount, y and total number of cups of coffee, x can be written as,
Total bill amount = Cost of a coffee × Number of cups of coffee
y = 2.50 × x
y = 2.50x
B.) The constant of proportionality between the number of cups of coffee and the total bill amount is 2.50.
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