Pre-Algebra Examples

$(3 x^{5} + 3 x^{3} + 3 x^{2} - 7 x + 12) \div (x^{2} + 4)$

Step 1

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

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

Step 2

Divide the highest order term in the dividend $3 x^{5}$ by the highest order term in divisor $x^{2}$ .

$3 x^{3}$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

Step 3

Multiply the new quotient term by the divisor.

$3 x^{3}$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

Step 4

The expression needs to be subtracted from the dividend, so change all the signs in $3 x^{5} + 0 + 12 x^{3}$

$3 x^{3}$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

Step 5

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

$3 x^{3}$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

Step 6

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

$3 x^{3}$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

Step 7

Divide the highest order term in the dividend $- 9 x^{3}$ by the highest order term in divisor $x^{2}$ .

$3 x^{3}$

$0 x^{2}$

$9 x$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

Step 8

Multiply the new quotient term by the divisor.

$3 x^{3}$

$0 x^{2}$

$9 x$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

$9 x^{3}$

$0$

$36 x$

Step 9

The expression needs to be subtracted from the dividend, so change all the signs in $- 9 x^{3} + 0 - 36 x$

$3 x^{3}$

$0 x^{2}$

$9 x$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

$9 x^{3}$

$0$

$36 x$

Step 10

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

$3 x^{3}$

$0 x^{2}$

$9 x$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

$9 x^{3}$

$0$

$36 x$

$3 x^{2}$

$29 x$

Step 11

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

$3 x^{3}$

$0 x^{2}$

$9 x$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

$9 x^{3}$

$0$

$36 x$

$3 x^{2}$

$29 x$

$12$

Step 12

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

$3 x^{3}$

$0 x^{2}$

$9 x$

$3$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

$9 x^{3}$

$0$

$36 x$

$3 x^{2}$

$29 x$

$12$

Step 13

Multiply the new quotient term by the divisor.

$3 x^{3}$

$0 x^{2}$

$9 x$

$3$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

$9 x^{3}$

$0$

$36 x$

$3 x^{2}$

$29 x$

$12$

$3 x^{2}$

$0$

$12$

Step 14

The expression needs to be subtracted from the dividend, so change all the signs in $3 x^{2} + 0 + 12$

$3 x^{3}$

$0 x^{2}$

$9 x$

$3$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

$9 x^{3}$

$0$

$36 x$

$3 x^{2}$

$29 x$

$12$

$3 x^{2}$

$0$

$12$

Step 15

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

$3 x^{3}$

$0 x^{2}$

$9 x$

$3$

$x^{2}$

$0 x$

$4$

$3 x^{5}$

$0 x^{4}$

$3 x^{3}$

$3 x^{2}$

$7 x$

$12$

$3 x^{5}$

$0$

$12 x^{3}$

$9 x^{3}$

$3 x^{2}$

$7 x$

$9 x^{3}$

$0$

$36 x$

$3 x^{2}$

$29 x$

$12$

$3 x^{2}$

$0$

$12$

$29 x$

$0$

Step 16

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

$3 x^{3} - 9 x + 3 + \frac{29 x}{x^{2} + 4}$