Is the set of monomials closed under multiplication? Which of the following gives a correct answer and an explanation? Group of answer choices

a. No; the product of two monomials could be a polynomial.

b. Yes; the sum of any two monomials is a monomial.

c. Yes; the product of any two monomials is a monomial.

d. No; the product of two monomials could be a rational number.

Solve the system of equations. y= 2x y= x^2 - 15

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?

Find the value of x in the diagram below. select the best answer from the choices provided