Please help!!
Will mark brainliest

Given that (x-3) is a factor of f(x)=x^3+ax^2-x-6, find a and hence the number of real roots or the equation f(x)=0

Select all the correct answers.natalie buys a new car. in the first month, the odometer on the car records 800 miles. from past experience, she expects to drive 900 miles per monthselect all the functions that can be used to find the number of miles, f(n), recorded on the odometer after n months.of(n) = 800n + 100f(n) = 9001 - 100f(n) = 900n + 800(1) = 800; }(n) = f(n - 1) + 900, for n > 2f(1) = 800; 1(n) = f(n − 1) + 100, for n > 2(1) = 900; }(n) = f(n - 1) + 800, for n > 2

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles