Which shows one way to determine the factors of x3 + 4x2 + 5x + 20 by grouping?

x(x2 + 4) + 5(x2 + 4)
x2(x + 4) + 5(x + 4)
x2(x + 5) + 4(x + 5)
x(x2 + 5) + 4x(x2 + 5)

1 number

if we use a graphing calculator, there is only one such number that satisfies the conclusion of the mean value theorem, that is, a number such that

where the right-hand side is the average rate of change of f on the interval [0.5,0.75], which is the slope of the secant line.

in the attached graph, the black line is the secant line which has its slope as the average rate of change of f on [0.5,0.75], while the orange line is the only tangent line to the graph of f in the interval that satisfies the mvt conclusion.

answer: (3,11) is your answer.