Which represents a function and why? i'm confused

A function has only one output (y) for every input (x). Easy way to identify a function on a graph is by the vertical line test. Imagine a vertical line going through the function, if the imagined line can go through exactly once, it's a function. (The top one is a function, the bottom is not.)

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500

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step-by-step explanation: