context: ###List of Questions
  (1) What is 1 + -9 - -5 - -1?
  (2) Solve -37 + 23 = 7*t for t.
  (3) Three letters picked without replacement from dxaxxaaxxxaax. What is prob of sequence aad?
  (4) Suppose a - 6*a + 3*j + 321 = 0, -342 = -5*a - 4*j. What is the greatest common divisor of 165 and a?
  (5) Convert 4.473208um to kilometers.
q_1: (1) What is 1 + -9 - -5 - -1?
q_2: (2) Solve -37 + 23 = 7*t for t.
q_3: (3) Three letters picked without replacement from dxaxxaaxxxaax. What is prob of sequence aad?
q_4: (4) Suppose a - 6*a + 3*j + 321 = 0, -342 = -5*a - 4*j. What is the greatest common divisor of 165 and a?
q_5: (5) Convert 4.473208um to kilometers.