Pre-Algebra Examples

$(- 15 x^{3} + 32 x^{2} - 36 x + 16) \div (5 x - 4)$

Step 1

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

$5 x$

$4$

$15 x^{3}$

$32 x^{2}$

$36 x$

$16$

Step 2

Divide the highest order term in the dividend $- 15 x^{3}$ by the highest order term in divisor $5 x$ .

				-	$3 x^{2}$
	$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$

Step 3

Multiply the new quotient term by the divisor.

			-	$3 x^{2}$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			-	$15 x^{3}$	+	$12 x^{2}$

Step 4

The expression needs to be subtracted from the dividend, so change all the signs in $- 15 x^{3} + 12 x^{2}$

			-	$3 x^{2}$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$

Step 5

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

			-	$3 x^{2}$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$

Step 6

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

			-	$3 x^{2}$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$

Step 7

Divide the highest order term in the dividend $20 x^{2}$ by the highest order term in divisor $5 x$ .

			-	$3 x^{2}$	+	$4 x$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$

Step 8

Multiply the new quotient term by the divisor.

			-	$3 x^{2}$	+	$4 x$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$
					+	$20 x^{2}$	-	$16 x$

Step 9

The expression needs to be subtracted from the dividend, so change all the signs in $20 x^{2} - 16 x$

			-	$3 x^{2}$	+	$4 x$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$
					-	$20 x^{2}$	+	$16 x$

Step 10

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

			-	$3 x^{2}$	+	$4 x$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$
					-	$20 x^{2}$	+	$16 x$
							-	$20 x$

Step 11

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

			-	$3 x^{2}$	+	$4 x$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$
					-	$20 x^{2}$	+	$16 x$
							-	$20 x$	+	$16$

Step 12

Divide the highest order term in the dividend $- 20 x$ by the highest order term in divisor $5 x$ .

			-	$3 x^{2}$	+	$4 x$	-	$4$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$
					-	$20 x^{2}$	+	$16 x$
							-	$20 x$	+	$16$

Step 13

Multiply the new quotient term by the divisor.

			-	$3 x^{2}$	+	$4 x$	-	$4$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$
					-	$20 x^{2}$	+	$16 x$
							-	$20 x$	+	$16$
							-	$20 x$	+	$16$

Step 14

The expression needs to be subtracted from the dividend, so change all the signs in $- 20 x + 16$

			-	$3 x^{2}$	+	$4 x$	-	$4$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$
					-	$20 x^{2}$	+	$16 x$
							-	$20 x$	+	$16$
							+	$20 x$	-	$16$

Step 15

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

			-	$3 x^{2}$	+	$4 x$	-	$4$
$5 x$	-	$4$	-	$15 x^{3}$	+	$32 x^{2}$	-	$36 x$	+	$16$
			+	$15 x^{3}$	-	$12 x^{2}$
					+	$20 x^{2}$	-	$36 x$
					-	$20 x^{2}$	+	$16 x$
							-	$20 x$	+	$16$
							+	$20 x$	-	$16$
										$0$

Step 16

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

$- 3 x^{2} + 4 x - 4$