Answer:
Domain = x ≥ 0
Range = y ≥ 20
Explanation:
The equation in slope-intercept form would look like this:
y = 4x + 20
The slope is $4 because that is the money that can be made depending on the week. Because he received a random $20 at the beginning, this is just an additional income.
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In this scenario, the domain (x-values) represent the number of weeks. The range (y-values) represent the total money made.
So the domain is asking, what is the lowest/highest amount of weeks he can save for? We know the number of weeks cannot be negative because he can't save for negative weeks. However, he could save for zero weeks. He can be saving for theoretically infinite weeks. Therefore, the domain is x ≥ 0.
The range is asking, how much money can he save? Since he starts out with a baseline of $20, this is the lowest amount of money he can have. If he were to save for an infinite amount of weeks, he could make an infinite amount of money. Therefore the range is y ≥ 20.