Algebra Examples

$(7 x^{3} + x^{2} - 4) \div (x - 5)$

Step 1

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

$x$

$5$

$7 x^{3}$

$x^{2}$

$0 x$

$4$

Step 2

Divide the highest order term in the dividend $7 x^{3}$ by the highest order term in divisor $x$ .

					$7 x^{2}$
	$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$

Step 3

Multiply the new quotient term by the divisor.

				$7 x^{2}$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			+	$7 x^{3}$	-	$35 x^{2}$

Step 4

The expression needs to be subtracted from the dividend, so change all the signs in $7 x^{3} - 35 x^{2}$

				$7 x^{2}$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$

Step 5

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

				$7 x^{2}$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$

Step 6

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

				$7 x^{2}$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$

Step 7

Divide the highest order term in the dividend $36 x^{2}$ by the highest order term in divisor $x$ .

				$7 x^{2}$	+	$36 x$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$

Step 8

Multiply the new quotient term by the divisor.

				$7 x^{2}$	+	$36 x$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$
					+	$36 x^{2}$	-	$180 x$

Step 9

The expression needs to be subtracted from the dividend, so change all the signs in $36 x^{2} - 180 x$

				$7 x^{2}$	+	$36 x$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$
					-	$36 x^{2}$	+	$180 x$

Step 10

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

				$7 x^{2}$	+	$36 x$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$
					-	$36 x^{2}$	+	$180 x$
							+	$180 x$

Step 11

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

				$7 x^{2}$	+	$36 x$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$
					-	$36 x^{2}$	+	$180 x$
							+	$180 x$	-	$4$

Step 12

Divide the highest order term in the dividend $180 x$ by the highest order term in divisor $x$ .

				$7 x^{2}$	+	$36 x$	+	$180$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$
					-	$36 x^{2}$	+	$180 x$
							+	$180 x$	-	$4$

Step 13

Multiply the new quotient term by the divisor.

				$7 x^{2}$	+	$36 x$	+	$180$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$
					-	$36 x^{2}$	+	$180 x$
							+	$180 x$	-	$4$
							+	$180 x$	-	$900$

Step 14

The expression needs to be subtracted from the dividend, so change all the signs in $180 x - 900$

				$7 x^{2}$	+	$36 x$	+	$180$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$
					-	$36 x^{2}$	+	$180 x$
							+	$180 x$	-	$4$
							-	$180 x$	+	$900$

Step 15

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

				$7 x^{2}$	+	$36 x$	+	$180$
$x$	-	$5$		$7 x^{3}$	+	$x^{2}$	+	$0 x$	-	$4$
			-	$7 x^{3}$	+	$35 x^{2}$
					+	$36 x^{2}$	+	$0 x$
					-	$36 x^{2}$	+	$180 x$
							+	$180 x$	-	$4$
							-	$180 x$	+	$900$
									+	$896$

Step 16

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

$7 x^{2} + 36 x + 180 + \frac{896}{x - 5}$