Given a simple high-school level math question, you are required to solve it and provide the final answer. The final answer is always a single number. These questions can range from a variety of topics like simple arithmetic, solving equations, converting a quantity from one unit to another, finding remainders/GCD/LCM, finding probabilities etc. Each question has only one correct answer. This answer can be a positive or negative integer, a fraction or a decimal number. If the answer is a negative number use the hyphen (e.g. -42) symbol for the minus sign. For decimal numbers, do not add extra zeros after the decimal point. For fractional numbers, separate the numerator and denominator using a forward slash (e.g. 3/25).

Let w = -31583/220 - -1550/11. What is the common denominator of -97/10 and w?
20

What is prob of sequence ew when two letters picked without replacement from {w: 1, e: 2}?
1/3

Let f(l) = -l**3 + 4*l**2 - 2*l - 2. Suppose 0 = -4*y + 3 + 5. Let d be f(y). Solve d*a - w = -9, -w + 5*w = -a - 9 for a.

-5