Algebra Examples

Use the long division method to find the result when $8 x^{3} - 10 x^{2} - x + 3$ is divided by $4 x - 3$

Step 1

Write the problem as a mathematical expression.

Use the long division method to find the result when $\frac{8 x^{3} - 10 x^{2} - x + 3}{4 x - 3}$

Step 2

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

$4 x$

$3$

$8 x^{3}$

$10 x^{2}$

$x$

$3$

Step 3

Divide the highest order term in the dividend $8 x^{3}$ by the highest order term in divisor $4 x$ .

					$2 x^{2}$
	$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$

Step 4

Multiply the new quotient term by the divisor.

				$2 x^{2}$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			+	$8 x^{3}$	-	$6 x^{2}$

Step 5

The expression needs to be subtracted from the dividend, so change all the signs in $8 x^{3} - 6 x^{2}$

				$2 x^{2}$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$

Step 6

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

				$2 x^{2}$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$

Step 7

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

				$2 x^{2}$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$

Step 8

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

				$2 x^{2}$	-	$x$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$

Step 9

Multiply the new quotient term by the divisor.

				$2 x^{2}$	-	$x$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$
					-	$4 x^{2}$	+	$3 x$

Step 10

The expression needs to be subtracted from the dividend, so change all the signs in $- 4 x^{2} + 3 x$

				$2 x^{2}$	-	$x$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$
					+	$4 x^{2}$	-	$3 x$

Step 11

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

				$2 x^{2}$	-	$x$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$
					+	$4 x^{2}$	-	$3 x$
							-	$4 x$

Step 12

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

				$2 x^{2}$	-	$x$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$
					+	$4 x^{2}$	-	$3 x$
							-	$4 x$	+	$3$

Step 13

Divide the highest order term in the dividend $- 4 x$ by the highest order term in divisor $4 x$ .

				$2 x^{2}$	-	$x$	-	$1$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$
					+	$4 x^{2}$	-	$3 x$
							-	$4 x$	+	$3$

Step 14

Multiply the new quotient term by the divisor.

				$2 x^{2}$	-	$x$	-	$1$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$
					+	$4 x^{2}$	-	$3 x$
							-	$4 x$	+	$3$
							-	$4 x$	+	$3$

Step 15

The expression needs to be subtracted from the dividend, so change all the signs in $- 4 x + 3$

				$2 x^{2}$	-	$x$	-	$1$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$
					+	$4 x^{2}$	-	$3 x$
							-	$4 x$	+	$3$
							+	$4 x$	-	$3$

Step 16

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

				$2 x^{2}$	-	$x$	-	$1$
$4 x$	-	$3$		$8 x^{3}$	-	$10 x^{2}$	-	$x$	+	$3$
			-	$8 x^{3}$	+	$6 x^{2}$
					-	$4 x^{2}$	-	$x$
					+	$4 x^{2}$	-	$3 x$
							-	$4 x$	+	$3$
							+	$4 x$	-	$3$
										$0$

Step 17

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

$2 x^{2} - x - 1$