Final answer:
To calculate the amount of money Greta will have after any number of weeks, the equation is: amount = 100 + (50 x number of weeks).
Step-by-step explanation:
To calculate the amount of money Greta will have after any number of weeks, we can use the formula:
Amount = 100 + (50 x number of weeks)
For example, if Greta saves for 4 weeks, the equation would be: Amount = 100 + (50 x 4) = 300.