In how many ways can a teacher arrange 6 students in the front row of a classroom with a total of 20 students?

Tracy solved the following problem. which of the statements is true? 9 ÷ 3 + 6 × 2 3 + 6 × 2 9 × 2 18 her answer is correct. her answer is incorrect. she should have multiplied before dividing. her answer is incorrect. she should have multiplied before adding. her answer is incorrect. she should have added before dividing.

Which of the symbols correctly relates the two numbers below check all that apply 6? 6

Could somebody me with this radical simplification?