Divide Polynomials: example 6.85

Find the quotient: $(2 x^{2} - 5 x - 3) \div (x - 3) .$

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Find the quotient: $(2 x^{2} - 3 x - 20) \div (x - 4) .$

How did it go?


Write it as a long division problem.
Be sure the dividend is in standard form.
Divide 2x² by x. Put the answer, 2x, in the quotient over the x term.
Multiply 2x times x − 3. Line up the like terms under the dividend.
Subtract 2x² − 6x from 2x² − 5x. Change the signs and then add. Then bring down the last term.
Divide x by x. Put the answer, 1, in the quotient over the constant term.
Multiply 1 times x − 3.
Subtract x − 3 from x − 3 by changing the signs and adding.
To check, multiply (x − 3)(2x + 1).
The result should be 2x² − 5x − 3.


Write it as a long division problem.
Be sure the dividend is in standard form.
Divide 2x² by x. Put the answer, 2x, in the quotient over the x term.
Multiply 2x times x − 3. Line up the like terms under the dividend.
Subtract 2x² − 6x from 2x² − 5x. Change the signs and then add. Then bring down the last term.
Divide x by x. Put the answer, 1, in the quotient over the constant term.
Multiply 1 times x − 3.
Subtract x − 3 from x − 3 by changing the signs and adding.
To check, multiply (x − 3)(2x + 1).
The result should be 2x² − 5x − 3.