Lesson 7.2: Adding and Subtracting Polynomials Answers

Which is true about the degree of the sum and difference of the polynomials 3x5y – 2x3y4 – 7xy3 and –8x5y + 2x3y4 + xy3?

Sydney is cutting the crust from the edges of her sandwich. The dimensions, in centimeters, of the sandwich is shown.

Profit is the difference between revenue and cost. The revenue, in dollars, of a company that manufactures televisions can be modeled by the polynomial 3x2 + 180x. The cost, in dollars, of producing the televisions can be modeled by 3x2 – 160x + 300. The variable x is the number of televisions sold.

What is true about the sum of the two polynomials?6s2t – 2st24s2t – 3st2

What is the sum of the polynomials?(–x2 + 9) + (–3x2 – 11x + 4)

What is the additive inverse of the polynomial –9xy2 + 6x2y – 5x3?

Which is true about the completely simplified difference of the polynomials a3b + 9a2b2 − 4ab5 and a3b − 3a2b2 + ab5?

Margot is sewing a ribbon on a seam along the perimeter of a square pillow. The side length of the pillow is 2x2+1 inches. She plans to make a similar pillow, including the ribbon, whose side length is 4x−7 inches. What expression can be used for the length of ribbon that she needs for both pillows, and what is the length if x = 3.5?

Profit is the difference between revenue and cost. The revenue, in dollars, of a company that manufactures cell phones can be modeled by the polynomial 2x2 + 55x + 10. The cost, in dollars, of producing the cell phones can be modeled by 2x2 – 15x – 40. The variable x represents the number of cell phones sold.

What is the difference of the polynomials?(–2x3y2 + 4x2y3 – 3xy4) – (6x4y – 5x2y3 – y5)