Precalculus Examples

$\frac{2 x^{4} - 8 x^{3} + 5 x^{2} + 2 x - 9}{x - 2}$

Step 1

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

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

Step 2

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

$2 x^{3}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

Step 3

Multiply the new quotient term by the divisor.

$2 x^{3}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

Step 4

The expression needs to be subtracted from the dividend, so change all the signs in $2 x^{4} - 4 x^{3}$

$2 x^{3}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

Step 5

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

$2 x^{3}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

Step 6

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

$2 x^{3}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

Step 7

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

$2 x^{3}$

$4 x^{2}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

Step 8

Multiply the new quotient term by the divisor.

$2 x^{3}$

$4 x^{2}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

Step 9

The expression needs to be subtracted from the dividend, so change all the signs in $- 4 x^{3} + 8 x^{2}$

$2 x^{3}$

$4 x^{2}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

Step 10

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

$2 x^{3}$

$4 x^{2}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

$3 x^{2}$

Step 11

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

$2 x^{3}$

$4 x^{2}$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

$3 x^{2}$

$2 x$

Step 12

Divide the highest order term in the dividend $- 3 x^{2}$ by the highest order term in divisor $x$ .

$2 x^{3}$

$4 x^{2}$

$3 x$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

$3 x^{2}$

$2 x$

Step 13

Multiply the new quotient term by the divisor.

$2 x^{3}$

$4 x^{2}$

$3 x$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

$3 x^{2}$

$2 x$

$3 x^{2}$

$6 x$

Step 14

The expression needs to be subtracted from the dividend, so change all the signs in $- 3 x^{2} + 6 x$

$2 x^{3}$

$4 x^{2}$

$3 x$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

$3 x^{2}$

$2 x$

$3 x^{2}$

$6 x$

Step 15

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

$2 x^{3}$

$4 x^{2}$

$3 x$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

$3 x^{2}$

$2 x$

$3 x^{2}$

$6 x$

$4 x$

Step 16

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

$2 x^{3}$

$4 x^{2}$

$3 x$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

$3 x^{2}$

$2 x$

$3 x^{2}$

$6 x$

$4 x$

$9$

Step 17

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

$2 x^{3}$

$4 x^{2}$

$3 x$

$4$

$x$

$2$

$2 x^{4}$

$8 x^{3}$

$5 x^{2}$

$2 x$

$9$

$2 x^{4}$

$4 x^{3}$

$5 x^{2}$

$4 x^{3}$

$8 x^{2}$

$3 x^{2}$

$2 x$

$3 x^{2}$

$6 x$

$4 x$

$9$

Step 18

Multiply the new quotient term by the divisor.

				$2 x^{3}$	-	$4 x^{2}$	-	$3 x$	-	$4$
$x$	-	$2$		$2 x^{4}$	-	$8 x^{3}$	+	$5 x^{2}$	+	$2 x$	-	$9$
			-	$2 x^{4}$	+	$4 x^{3}$
					-	$4 x^{3}$	+	$5 x^{2}$
					+	$4 x^{3}$	-	$8 x^{2}$
							-	$3 x^{2}$	+	$2 x$
							+	$3 x^{2}$	-	$6 x$
									-	$4 x$	-	$9$
									-	$4 x$	+	$8$

Step 19

The expression needs to be subtracted from the dividend, so change all the signs in $- 4 x + 8$

				$2 x^{3}$	-	$4 x^{2}$	-	$3 x$	-	$4$
$x$	-	$2$		$2 x^{4}$	-	$8 x^{3}$	+	$5 x^{2}$	+	$2 x$	-	$9$
			-	$2 x^{4}$	+	$4 x^{3}$
					-	$4 x^{3}$	+	$5 x^{2}$
					+	$4 x^{3}$	-	$8 x^{2}$
							-	$3 x^{2}$	+	$2 x$
							+	$3 x^{2}$	-	$6 x$
									-	$4 x$	-	$9$
									+	$4 x$	-	$8$

Step 20

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

				$2 x^{3}$	-	$4 x^{2}$	-	$3 x$	-	$4$
$x$	-	$2$		$2 x^{4}$	-	$8 x^{3}$	+	$5 x^{2}$	+	$2 x$	-	$9$
			-	$2 x^{4}$	+	$4 x^{3}$
					-	$4 x^{3}$	+	$5 x^{2}$
					+	$4 x^{3}$	-	$8 x^{2}$
							-	$3 x^{2}$	+	$2 x$
							+	$3 x^{2}$	-	$6 x$
									-	$4 x$	-	$9$
									+	$4 x$	-	$8$
											-	$17$

Step 21

The final answer is the quotient plus the remainder over the divisor.

$2 x^{3} - 4 x^{2} - 3 x - 4 - \frac{17}{x - 2}$