What is the answer of this question I don’t know what it is

If x-1 and x+3 are the factors of x3+10x2+ax+b find a and b

Which of the following is an example of a rational number? a. π b. √ 9 c. √ 8 d. 3.8362319

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