Pre-Algebra Examples

$\frac{12 x^{3} - 11 x^{2} + 9 x + 18}{4 x + 3}$

Step 1

Set up the polynomials to be divided. If there is not a term for every exponent, insert one with a value of $0$ .

$4 x$

$3$

$12 x^{3}$

$11 x^{2}$

$9 x$

$18$

Step 2

Divide the highest order term in the dividend $12 x^{3}$ by the highest order term in divisor $4 x$ .

					$3 x^{2}$
	$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$

Step 3

Multiply the new quotient term by the divisor.

				$3 x^{2}$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			+	$12 x^{3}$	+	$9 x^{2}$

Step 4

The expression needs to be subtracted from the dividend, so change all the signs in $12 x^{3} + 9 x^{2}$

				$3 x^{2}$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$

Step 5

After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.

				$3 x^{2}$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$

Step 6

Pull the next terms from the original dividend down into the current dividend.

				$3 x^{2}$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$

Step 7

Divide the highest order term in the dividend $- 20 x^{2}$ by the highest order term in divisor $4 x$ .

				$3 x^{2}$	-	$5 x$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$

Step 8

Multiply the new quotient term by the divisor.

				$3 x^{2}$	-	$5 x$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$
					-	$20 x^{2}$	-	$15 x$

Step 9

The expression needs to be subtracted from the dividend, so change all the signs in $- 20 x^{2} - 15 x$

				$3 x^{2}$	-	$5 x$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$
					+	$20 x^{2}$	+	$15 x$

Step 10

After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.

				$3 x^{2}$	-	$5 x$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$
					+	$20 x^{2}$	+	$15 x$
							+	$24 x$

Step 11

Pull the next terms from the original dividend down into the current dividend.

				$3 x^{2}$	-	$5 x$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$
					+	$20 x^{2}$	+	$15 x$
							+	$24 x$	+	$18$

Step 12

Divide the highest order term in the dividend $24 x$ by the highest order term in divisor $4 x$ .

				$3 x^{2}$	-	$5 x$	+	$6$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$
					+	$20 x^{2}$	+	$15 x$
							+	$24 x$	+	$18$

Step 13

Multiply the new quotient term by the divisor.

				$3 x^{2}$	-	$5 x$	+	$6$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$
					+	$20 x^{2}$	+	$15 x$
							+	$24 x$	+	$18$
							+	$24 x$	+	$18$

Step 14

The expression needs to be subtracted from the dividend, so change all the signs in $24 x + 18$

				$3 x^{2}$	-	$5 x$	+	$6$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$
					+	$20 x^{2}$	+	$15 x$
							+	$24 x$	+	$18$
							-	$24 x$	-	$18$

Step 15

After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.

				$3 x^{2}$	-	$5 x$	+	$6$
$4 x$	+	$3$		$12 x^{3}$	-	$11 x^{2}$	+	$9 x$	+	$18$
			-	$12 x^{3}$	-	$9 x^{2}$
					-	$20 x^{2}$	+	$9 x$
					+	$20 x^{2}$	+	$15 x$
							+	$24 x$	+	$18$
							-	$24 x$	-	$18$
										$0$

Step 16

Since the remander is $0$ , the final answer is the quotient.

$3 x^{2} - 5 x + 6$