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).
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Question: Suppose -s = 4*r - 45, -s - r + 4*r = -38. Calculate the remainder when 121 is divided by s.

Answer: 39


Question: Let s = 11 + -3. Solve -y - s = y for y.

Answer: -4


Question: Solve 5*u + 3*w = 4*u + 4, 20 = 5*u + 4*w for u.

Answer:
4