Pre-Algebra Examples

$(8 x^{4} - 3 x + 2 x^{2} - 5) \div (x^{2} + 4)$

Step 1

Move $- 3 x$ .

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

Step 2

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

$x^{2}$

$0 x$

$4$

$8 x^{4}$

$0 x^{3}$

$2 x^{2}$

$3 x$

$5$

Step 3

Divide the highest order term in the dividend $8 x^{4}$ by the highest order term in divisor $x^{2}$ .

$8 x^{2}$

$x^{2}$

$0 x$

$4$

$8 x^{4}$

$0 x^{3}$

$2 x^{2}$

$3 x$

$5$

Step 4

Multiply the new quotient term by the divisor.

$8 x^{2}$

$x^{2}$

$0 x$

$4$

$8 x^{4}$

$0 x^{3}$

$2 x^{2}$

$3 x$

$5$

$8 x^{4}$

$0$

$32 x^{2}$

Step 5

The expression needs to be subtracted from the dividend, so change all the signs in $8 x^{4} + 0 + 32 x^{2}$

$8 x^{2}$

$x^{2}$

$0 x$

$4$

$8 x^{4}$

$0 x^{3}$

$2 x^{2}$

$3 x$

$5$

$8 x^{4}$

$0$

$32 x^{2}$

Step 6

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

$8 x^{2}$

$x^{2}$

$0 x$

$4$

$8 x^{4}$

$0 x^{3}$

$2 x^{2}$

$3 x$

$5$

$8 x^{4}$

$0$

$32 x^{2}$

$30 x^{2}$

Step 7

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

						$8 x^{2}$
$x^{2}$	+	$0 x$	+	$4$		$8 x^{4}$	+	$0 x^{3}$	+	$2 x^{2}$	-	$3 x$	-	$5$
					-	$8 x^{4}$	-	$0$	-	$32 x^{2}$
									-	$30 x^{2}$	-	$3 x$	-	$5$

Step 8

Divide the highest order term in the dividend $- 30 x^{2}$ by the highest order term in divisor $x^{2}$ .

						$8 x^{2}$	+	$0 x$	-	$30$
$x^{2}$	+	$0 x$	+	$4$		$8 x^{4}$	+	$0 x^{3}$	+	$2 x^{2}$	-	$3 x$	-	$5$
					-	$8 x^{4}$	-	$0$	-	$32 x^{2}$
									-	$30 x^{2}$	-	$3 x$	-	$5$

Step 9

Multiply the new quotient term by the divisor.

						$8 x^{2}$	+	$0 x$	-	$30$
$x^{2}$	+	$0 x$	+	$4$		$8 x^{4}$	+	$0 x^{3}$	+	$2 x^{2}$	-	$3 x$	-	$5$
					-	$8 x^{4}$	-	$0$	-	$32 x^{2}$
									-	$30 x^{2}$	-	$3 x$	-	$5$
									-	$30 x^{2}$	+	$0$	-	$120$

Step 10

The expression needs to be subtracted from the dividend, so change all the signs in $- 30 x^{2} + 0 - 120$

						$8 x^{2}$	+	$0 x$	-	$30$
$x^{2}$	+	$0 x$	+	$4$		$8 x^{4}$	+	$0 x^{3}$	+	$2 x^{2}$	-	$3 x$	-	$5$
					-	$8 x^{4}$	-	$0$	-	$32 x^{2}$
									-	$30 x^{2}$	-	$3 x$	-	$5$
									+	$30 x^{2}$	-	$0$	+	$120$

Step 11

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

						$8 x^{2}$	+	$0 x$	-	$30$
$x^{2}$	+	$0 x$	+	$4$		$8 x^{4}$	+	$0 x^{3}$	+	$2 x^{2}$	-	$3 x$	-	$5$
					-	$8 x^{4}$	-	$0$	-	$32 x^{2}$
									-	$30 x^{2}$	-	$3 x$	-	$5$
									+	$30 x^{2}$	-	$0$	+	$120$
											-	$3 x$	+	$115$

Step 12

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

$8 x^{2} - 30 + \frac{- 3 x + 115}{x^{2} + 4}$