Each cd at a music store is sold for 10$ if n represents the number of cds sold which equation could be used to find the total number of dollars d the store receives from cd sale

Can someone me and plz do the problem

Worth 100 points need the answers asap first row -x^2 2x^2 (x/2)^2 x^2 x is less than 2 x is greater than 2 x is less than or equal to 2 x is greater than or equal to 2 second row -5 -5/2 4 5 •2 is less than x& x is less than 4 •2 is less than or equal to x & x is less than or equal to 4 •2 is less than or equal to x& x is less than 4 •2 is less than x& x is less than or equal to 4

Which equation can be solved to find one of the missing side lengths in the triangle? cos(60o) = cos(60o) = cos(60o) = cos(60o) = mark this and return