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).

Input: Consider Input: Solve -k = -4*a + 15, 0 = 6*k - 10*k + a + 15 for k.

Output: 5


Input: Consider Input: Suppose 4*i + i = 45. Suppose 3*u = i*u - 132. Let v = -82 + 147. Calculate the remainder when v is divided by u.

Output: 21


Input: Consider Input: Solve -5*f - 36 = 4*d, 5*f - d = 4*d for f.


Output: -4