SOLUTION: Bethany plans to collect and save the new Eisenhower coins worth one dollar. Her grandmother gave her 20 coins to start her collection. Each week at the Post Office, her father get

Question 22649: Bethany plans to collect and save the new Eisenhower coins worth one dollar. Her grandmother gave her 20 coins to start her collection. Each week at the Post Office, her father gets 4 coins in change from the vending machines and gives them to Bethany. Bethany realized that the total number of coins, y, she has in her collection after x weeks can be caculated by the function y = 4x + 20.
Is the domain of the function best described as all real number, all integer, all whole numbers, or all whole numbers greater than 20?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Make a list of what happened.
Grandma gave her 20
Dad then gave her 4; she now has 20+4
Dad gives her 2nd 4; she now has 20+2(4)
Dad gives her 3rd 4; she now has 20+3(4)
etc.
Notice you do not add as you go along because
you want to see the pattern.
See how this relates to y=20+4x ???
Do you see the Domain? Is it all whole numbers?
Cheers,
Stan H.
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