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: Let n(s) = s**2 + 3*s + 2. Let z be n(-2). Suppose z = j + j - 70. Suppose -j - 56 = -t. What is the highest common factor of 13 and t?

Answer: 13


Question: Suppose 0 = 5*a + 3*q - 104, 0 = 5*a - 0*q - 3*q - 116. Suppose 0 = -b - 3*b + 5*n + 88, b - 3*n - a = 0. Suppose b = -0*f + 2*f. What is the tens digit of f?

Answer: 1


Question: Let y be ((-28)/5)/((-3)/90). Calculate the highest common factor of y and 21.

Answer:
21