What is the ninth triangular number?

Use the x-intercept method to find all real solutions of the equation.x^3-10x^2+27x-18=0

The given dot plot represents the average daily temperatures, in degrees fahrenheit, recorded in a town during the first 15 days of september. if the dot plot is converted to a box plot, the first quartile would be drawn at __ , and the third quartile would be drawn at link to the chart is here

If f(x) = 4x - 3 and g(x) = x + 4, find (f - g) (x)