explain the error in detail

Question

(x⁴+3x²-x-8) (x+3)

1 3 0 -1 -8

3 3 18 54 159

1 6 18 53 151

x³+6x²+18x+204

Answer 1

There MUST be a placeholder inserted for the "cubic" term so we add in 0x³

This makes the result of the division x³ + 3x² + 12x + 35 with remainder 97 which can also be written as x³ + 3x² + 12x + 35 + 97/(x - 3)