Y=30x.
Whatever the number of months is you times by 30, the amount she added each month. If she had started with a certain amount you would add that to the equation. Y is the total money in the account.
You haven't written the question properly because we have nothing to base y on.
Answer:
Divide the central angle in radians by 2 and perform the sine function on it. Divide the chord length by double the result of step 1. This calculation gives you the radius. Multiply the radius by the central angle to get the arc length.
