Ireally need with this! i don't really understand linear equation stuff and i asked my teacher about it but she isn't . i only need with one question. if you need anything else to answer it just tell me.

use the system of linear equations you wrote to solve for the variables p and q. show all work.

here's the linear equations i wrote down:
supply: p = 1/40q + 9.75
demand: p = -1/50q + 12

Unaware that 35% of the 10000 voters in his constituency support him, a politician decides to estimate his political strength. a sample of 200 voters shows that 40% support him. a. what is the population? b. what is the parameter of interest? state its value c. what is the statistics of the interest? state its value d. compare your answers in (b) and (c) is it surprising they are different? if the politician were to sample another 200 voters, which of the two numbers would most likely change? explain