More Synthetic Division Examples
Synthetic division saves time, especially with more complex polynomials. For example, when dividing 2x3−15x2+21x+24 by x−3, we set up the synthetic division with k=3 and work through the process. The result shows a quotient of 2x2−9x−6 with a remainder of 6, written as 2x2−9x−6+x−36.
When using synthetic division, always remember to include zeros for any missing terms in your polynomial. For instance, in 2x4−7x2−4x+2 divided by x+1, we need to include a zero for the missing x3 term before starting the division process.
The final answer format depends on whether the divisor is a factor. If the remainder is zero as in the fifth example where $3x^4-25x^3+27x^2+6x+7$ divided by $x-7$ gives a remainder of 0, then the divisor is a factor and the answer is just the quotient. Otherwise, write the answer with the remainder over the divisor.
Pro Tip: When dividing by (x+a) instead of (x−k), use k=−a in your synthetic division. For example, to divide by (x+1), use k=−1 in your setup.