What is the difference between the number of solutions for a two-step equation and for a two-step inequality

Brian, chris, and damien took a math test that had 20 questions. the number of questions brian got right is 14 more than the number of questions chris got right. damien correctly answered 2 less than the number of questions chris answered correctly. if brian and damien have the same score, which statement is true?

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

The value of the expression 16-^3/4 8 1/8 -6 6 1/40 1/64