On the Subject of Algebra

“Why do we need to study algebra? We’ll never use it in real life...” Anybody else remember saying that?

• The module consists of a number pad and two screens.
• In three stages, the module displays an equation involving the variables a, b and c, respectively.
• Solve the equation for a, b or c and enter the answer to progress to the next stage.
• In each equation, the variables x, y and z may appear. Calculate their values using the columns of the following table:

x = n		y = i − p		z = m + t × d
n = sum of digits in the serial number		i = number of indicators p = number of ports		m = number of modules t = number of AA batteries d = number of D batteries
3 or more battery holders present?	+2	2 or fewer battery holders present?	−2	No battery holders present?	+3
RJ-45 port present?	−1	Serial port present?	+3	Parallel port present?	−6
Lit BOB indicator present?	+4	Unlit FRQ indicator present?	−5	Lit MSA indicator present?	+2
Serial number contains a vowel?	−3	Sum of the serial number digits is prime?	+4	Sum of the serial number digits is divisible by 3?	+1