TASK DEFINITION: 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).
PROBLEM: What is the next term in -147, -149, -151, -153?

SOLUTION: -155

PROBLEM: How many hours are there in 40.53144 weeks?

SOLUTION: 6809.28192

PROBLEM: Suppose -6*m = -m. Let c(d) = 2*d + 5. Let w be c(m). Solve -4*a - 20 = 5*r, -3*r - w*a = -a + 12 for r.

SOLUTION:
-4