x³ - 7x² + 8
x + 1 (* x²) | x³ + x²
_________________ (subtract)
 0x³ - 8x² + 8
 - 8x² + 8
x + 1 (* -8x) | -8x² - 8x
__________________ (subtract)
 0x² + 8x + 8
 8x + 8
x + 1 (* 8) | 8x + 8
__________________ (subtract
 0x + 0
Therefore, the result is x² - 8x + 8