Algebra Examples

$(- 2 x^{2} + x^{3} - 75) \div (x - 5)$

Step 1

Reorder $- 2 x^{2}$ and $x^{3}$ .

$\frac{x^{3} - 2 x^{2} - 75}{x - 5}$

Step 2

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

$x$

$5$

$x^{3}$

$2 x^{2}$

$0 x$

$75$

Step 3

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

					$x^{2}$
	$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$

Step 4

Multiply the new quotient term by the divisor.

				$x^{2}$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			+	$x^{3}$	-	$5 x^{2}$

Step 5

The expression needs to be subtracted from the dividend, so change all the signs in $x^{3} - 5 x^{2}$

				$x^{2}$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$

Step 6

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

				$x^{2}$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$

Step 7

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

				$x^{2}$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$

Step 8

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

				$x^{2}$	+	$3 x$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$

Step 9

Multiply the new quotient term by the divisor.

				$x^{2}$	+	$3 x$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$
					+	$3 x^{2}$	-	$15 x$

Step 10

The expression needs to be subtracted from the dividend, so change all the signs in $3 x^{2} - 15 x$

				$x^{2}$	+	$3 x$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$
					-	$3 x^{2}$	+	$15 x$

Step 11

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

				$x^{2}$	+	$3 x$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$
					-	$3 x^{2}$	+	$15 x$
							+	$15 x$

Step 12

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

				$x^{2}$	+	$3 x$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$
					-	$3 x^{2}$	+	$15 x$
							+	$15 x$	-	$75$

Step 13

Divide the highest order term in the dividend $15 x$ by the highest order term in divisor $x$ .

				$x^{2}$	+	$3 x$	+	$15$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$
					-	$3 x^{2}$	+	$15 x$
							+	$15 x$	-	$75$

Step 14

Multiply the new quotient term by the divisor.

				$x^{2}$	+	$3 x$	+	$15$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$
					-	$3 x^{2}$	+	$15 x$
							+	$15 x$	-	$75$
							+	$15 x$	-	$75$

Step 15

The expression needs to be subtracted from the dividend, so change all the signs in $15 x - 75$

				$x^{2}$	+	$3 x$	+	$15$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$
					-	$3 x^{2}$	+	$15 x$
							+	$15 x$	-	$75$
							-	$15 x$	+	$75$

Step 16

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

				$x^{2}$	+	$3 x$	+	$15$
$x$	-	$5$		$x^{3}$	-	$2 x^{2}$	+	$0 x$	-	$75$
			-	$x^{3}$	+	$5 x^{2}$
					+	$3 x^{2}$	+	$0 x$
					-	$3 x^{2}$	+	$15 x$
							+	$15 x$	-	$75$
							-	$15 x$	+	$75$
										$0$

Step 17

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

$x^{2} + 3 x + 15$