Paolo Ruffini (1765-1822) was an Italian mathematician who established a shorter method for dividing polynomials when the divisor is a binomial of the form x - a.
Ruffini's Rule
To explain the steps to apply in Ruffini's rule, we will take two examples:
First Example of Ruffini's Rule
Divide:
1. If the polynomial is not complete, we complete it by adding the missing terms with zeros.

2. We place the coefficients of the dividend in a line.

3. Below on the left, we place the opposite of the independent term of the divisor:
.


4. We draw a line and bring down the first coefficient
.




5. We multiply that coefficient
by the divisor
and place it below the next term
.




6. We add the two coefficients
.




7. We repeat the previous process:
and
.




We repeat the process again:
and
.




We repeat again:
and
.




8. The last number obtained,
, is the remainder.
9. The quotient is a polynomial of degree one unit less than the dividend, and whose coefficients are those we have obtained.
Quotient:
Remainder:
Second Example of Ruffini's Rule
Divide using Ruffini's rule: 
1. If the polynomial is not complete, we complete it by adding the missing terms with zeros.

2. We place the coefficients of the dividend in a line.

3. Below on the left, we place the opposite of the independent term of the divisor:
.


4. We draw a line and bring down the first coefficient
.




5. We multiply that coefficient
by the divisor
and place it below the next term
.




6. We add the two coefficients
.



7. We repeat steps
and
until the end.


8. The quotient is a polynomial of degree one unit less than the dividend, and whose coefficients are those we have obtained.
Quotient:
Remainder:
Summarize with AI:








