3x+15=3(x+5) help please?

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?

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

What is the number 321,000,000 in scientific notation? also what is the number? ?