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).

What is twenty-one eighths of a centimeter in micrometers?
26250

Suppose 49 = 4*i - 3*i. Suppose b + 3*q = 20, 0 = -0*b + 4*b + 4*q - 40. Suppose d + o = 11, -5*o = b*d - d - i. Solve 0 = -w + 1, -w + d = c + w for c.
4

Suppose 36 = f + 3*f. Let s = -5 + f. Solve -3*p - 4*r = 0, -4 = -0*p - 2*p - s*r for p.

-4