Algebra Examples

Use the long division method to find the result when $12 x^{3} - 17 x^{2} - 13 x - 2$ is divided by $4 x + 1$

Step 1

Write the problem as a mathematical expression.

Use the long division method to find the result when $\frac{12 x^{3} - 17 x^{2} - 13 x - 2}{4 x + 1}$

Step 2

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

$4 x$

$1$

$12 x^{3}$

$17 x^{2}$

$13 x$

$2$

Step 3

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

					$3 x^{2}$
	$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$

Step 4

Multiply the new quotient term by the divisor.

				$3 x^{2}$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			+	$12 x^{3}$	+	$3 x^{2}$

Step 5

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

				$3 x^{2}$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$

Step 6

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

				$3 x^{2}$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$

Step 7

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

				$3 x^{2}$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$

Step 8

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

				$3 x^{2}$	-	$5 x$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$

Step 9

Multiply the new quotient term by the divisor.

				$3 x^{2}$	-	$5 x$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$
					-	$20 x^{2}$	-	$5 x$

Step 10

The expression needs to be subtracted from the dividend, so change all the signs in $- 20 x^{2} - 5 x$

				$3 x^{2}$	-	$5 x$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$
					+	$20 x^{2}$	+	$5 x$

Step 11

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

				$3 x^{2}$	-	$5 x$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$
					+	$20 x^{2}$	+	$5 x$
							-	$8 x$

Step 12

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

				$3 x^{2}$	-	$5 x$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$
					+	$20 x^{2}$	+	$5 x$
							-	$8 x$	-	$2$

Step 13

Divide the highest order term in the dividend $- 8 x$ by the highest order term in divisor $4 x$ .

				$3 x^{2}$	-	$5 x$	-	$2$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$
					+	$20 x^{2}$	+	$5 x$
							-	$8 x$	-	$2$

Step 14

Multiply the new quotient term by the divisor.

				$3 x^{2}$	-	$5 x$	-	$2$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$
					+	$20 x^{2}$	+	$5 x$
							-	$8 x$	-	$2$
							-	$8 x$	-	$2$

Step 15

The expression needs to be subtracted from the dividend, so change all the signs in $- 8 x - 2$

				$3 x^{2}$	-	$5 x$	-	$2$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$
					+	$20 x^{2}$	+	$5 x$
							-	$8 x$	-	$2$
							+	$8 x$	+	$2$

Step 16

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

				$3 x^{2}$	-	$5 x$	-	$2$
$4 x$	+	$1$		$12 x^{3}$	-	$17 x^{2}$	-	$13 x$	-	$2$
			-	$12 x^{3}$	-	$3 x^{2}$
					-	$20 x^{2}$	-	$13 x$
					+	$20 x^{2}$	+	$5 x$
							-	$8 x$	-	$2$
							+	$8 x$	+	$2$
										$0$

Step 17

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

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