Which of the following shows that polynomials are closed under subtraction when two polynomials, (4x2 − 8x − 7) − (3x2 − 5x + 16), are subtracted?

x2 − 3x − 23; will be a polynomial
x2 − 3x − 23; may or may not be a polynomial
x2 − 13x + 9; will be a polynomial
x2 − 13x + 9; may or may not be a polynomial

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? 1. define a variable for the situation. 2. write an inequality that represents her profit. note: revenue is money coming in. cost is money going out. profit is the difference between the revenue and the cost. in other words: revenue - costs profit 3.using words, describe how many windows she must sell to have a profit of at least $48,000.