Pre-Algebra Examples

$(2 x^{3} + 3 x - 65) \div (2 x + 13)$

Step 1

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

$2 x$

$13$

$2 x^{3}$

$0 x^{2}$

$3 x$

$65$

Step 2

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

					$x^{2}$
	$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$

Step 3

Multiply the new quotient term by the divisor.

				$x^{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			+	$2 x^{3}$	+	$13 x^{2}$

Step 4

The expression needs to be subtracted from the dividend, so change all the signs in $2 x^{3} + 13 x^{2}$

				$x^{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$

Step 5

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

				$x^{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$

Step 6

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

				$x^{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$

Step 7

Divide the highest order term in the dividend $- 13 x^{2}$ by the highest order term in divisor $2 x$ .

				$x^{2}$	-	$\frac{13 x}{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$

Step 8

Multiply the new quotient term by the divisor.

				$x^{2}$	-	$\frac{13 x}{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$
					-	$13 x^{2}$	-	$\frac{169 x}{2}$

Step 9

The expression needs to be subtracted from the dividend, so change all the signs in $- 13 x^{2} - \frac{169 x}{2}$

				$x^{2}$	-	$\frac{13 x}{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$
					+	$13 x^{2}$	+	$\frac{169 x}{2}$

Step 10

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

				$x^{2}$	-	$\frac{13 x}{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$
					+	$13 x^{2}$	+	$\frac{169 x}{2}$
							+	$\frac{175 x}{2}$

Step 11

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

				$x^{2}$	-	$\frac{13 x}{2}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$
					+	$13 x^{2}$	+	$\frac{169 x}{2}$
							+	$\frac{175 x}{2}$	-	$65$

Step 12

Divide the highest order term in the dividend $\frac{175 x}{2}$ by the highest order term in divisor $2 x$ .

				$x^{2}$	-	$\frac{13 x}{2}$	+	$\frac{175}{4}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$
					+	$13 x^{2}$	+	$\frac{169 x}{2}$
							+	$\frac{175 x}{2}$	-	$65$

Step 13

Multiply the new quotient term by the divisor.

				$x^{2}$	-	$\frac{13 x}{2}$	+	$\frac{175}{4}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$
					+	$13 x^{2}$	+	$\frac{169 x}{2}$
							+	$\frac{175 x}{2}$	-	$65$
							+	$\frac{175 x}{2}$	+	$\frac{2275}{4}$

Step 14

The expression needs to be subtracted from the dividend, so change all the signs in $\frac{175 x}{2} + \frac{2275}{4}$

				$x^{2}$	-	$\frac{13 x}{2}$	+	$\frac{175}{4}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$
					+	$13 x^{2}$	+	$\frac{169 x}{2}$
							+	$\frac{175 x}{2}$	-	$65$
							-	$\frac{175 x}{2}$	-	$\frac{2275}{4}$

Step 15

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

				$x^{2}$	-	$\frac{13 x}{2}$	+	$\frac{175}{4}$
$2 x$	+	$13$		$2 x^{3}$	+	$0 x^{2}$	+	$3 x$	-	$65$
			-	$2 x^{3}$	-	$13 x^{2}$
					-	$13 x^{2}$	+	$3 x$
					+	$13 x^{2}$	+	$\frac{169 x}{2}$
							+	$\frac{175 x}{2}$	-	$65$
							-	$\frac{175 x}{2}$	-	$\frac{2275}{4}$
									-	$\frac{2535}{4}$

Step 16

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

$x^{2} - \frac{13 x}{2} + \frac{175}{4} - \frac{2535}{4 (2 x + 13)}$