Answer:
f(x) = 12x³ - 19x² + 17x - 17
Step-by-step explanation:
We can the numerator by multiplying the denominator by the quotient, and then adding the remainder.
We're given a denominator of 4x - 5
a quotient of 3x² - x + 3
and a remainder of -2
so the original numerator is:
(4x - 5)(3x² - x + 3) - 2
= 12x³ - 4x² + 12x - 15x² + 5x - 15 - 2
= 12x³ - 19x² + 17x - 17
Let's test that by dividing it by 4x -5 with long division:
[tex]\ \ \ \ \ \ \ \ \ \ 3x^2 - x + 3\\4x - 5\overline{)12x^3 - 19x^2 + 17x - 17}\\.\ \ \ \ \ \ \ \ \ \underline{2x^3 - 15x^2}\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ -4x^2 + 17x\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \underline{-4x^2 + 5x} \\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 12x - 17\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \underline{12x - 15}\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 2R[/tex]
That matches, so we know our answer's right, and:
f(x) = 12x³ - 19x² + 17x - 17
