
Start with this:
----------------------
2x - 1 )6x³ + 19x² + x - 10
2x divides into 6x³ to give 3x²
Put that at the top, above the 19x²
3x²
----------------------
2x - 1 )6x³ + 19x² + x - 10
Multiply the 3x² by the 2x - 1 to get 6x³ - 3x²,
so write that at the bottom and draw a line:
3x²
----------------------
2x - 1 )6x³ + 19x² + x - 10
6x³ - 3x²
----------
Now subtract, by mentally changing the signs on
the bottom row. We get 22x², so we write that
at the bottom, and bring down the next term x:
3x²
----------------------
2x - 1 )6x³ + 19x² + x - 10
6x³ - 3x²
----------
22x² + x
2x divides into 22x² to give 11x
Put that at the top above the x
3x² + 11x
----------------------
2x - 1 )6x³ + 19x² + x - 10
6x³ - 3x²
----------
22x² + x
Multiply the 11x by the 2x - 1 to get 22x² - 11x,
so write that at the bottom and draw a line:
3x² + 11x + 6
----------------------
2x - 1 )6x³ + 19x² + x - 10
6x³ - 3x²
----------
22x² + x
22x² - 11x
----------
Now subtract, by mentally changing the signs on
the bottom row. We get 12x, so we write that
at the bottom, and bring down the next term -10:
3x² + 11x
----------------------
2x - 1 )6x³ + 19x² + x - 10
6x³ - 3x²
----------
22x² + x
22x² - 11x
----------
12x - 10
2x divides into 12x to give 6
Put that at the top above the -10
3x² + 11x + 6
----------------------
2x - 1 )6x³ + 19x² + x - 10
6x³ - 3x²
----------
22x² + x
22x² - 11x
----------
12x - 10
Multiply the 6 by the 2x - 1 to get 12x - 6,
so write that at the bottom and draw a line:
3x² + 11x + 6
----------------------
2x - 1 )6x³ + 19x² + x - 10
6x³ - 3x²
----------
22x² + x
22x² - 11x
----------
12x - 10
12x - 6
--------
Now subtract, by mentally changing the signs on
the bottom row. We get -4, so we write that
at the bottom, and we're finished because there
are no more terms to bring down:
3x² + 11x + 6
----------------------
2x - 1 )6x³ + 19x² + x - 10
6x³ - 3x²
----------
22x² + x
22x² - 11x
----------
12x - 10
12x - 6
--------
- 4
Now we write the answer using
or if you like:
Edwin