At a music store, CDs are sold at $5 each and DVDs are sold at $7 each. If one day it sold 10 more CDs than DVDs, and makes a total of $530, how many CDs and DVDs did it sell respectively?

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.