Estimate decimals use a benchmark ; )

Use set builder notation to represent the following set: { -3, -2, -1, 0}

Does the problem involve permutations or? combinations? do not solve. the matching section of an exam has 4 questions and 7 possible answers. in how many different ways can a student answer the 4 ? questions, if none of the answer choices can be? repeated?

What is the value of x in the equation 1.5x+4-3=4.5(x-2)?