a stockbroker charges customers $30 to open an account and $15 per month to manage the account. write an equation to represent the number of months, n, an account has been open if the total cost is $360

Will mark the brainliest.paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each?