Pre-Algebra Examples

$(x^{4} - 9 x^{3} + 26 x + 12) \div (2 x - 3)$

Step 1

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

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

Step 2

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

$\frac{x^{3}}{2}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

Step 3

Multiply the new quotient term by the divisor.

$\frac{x^{3}}{2}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

Step 4

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

$\frac{x^{3}}{2}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

Step 5

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

$\frac{x^{3}}{2}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

Step 6

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

$\frac{x^{3}}{2}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

Step 7

Divide the highest order term in the dividend $- \frac{15 x^{3}}{2}$ by the highest order term in divisor $2 x$ .

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

Step 8

Multiply the new quotient term by the divisor.

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

Step 9

The expression needs to be subtracted from the dividend, so change all the signs in $- \frac{15 x^{3}}{2} + \frac{45 x^{2}}{4}$

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

Step 10

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

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

Step 11

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

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

Step 12

Divide the highest order term in the dividend $- \frac{45 x^{2}}{4}$ by the highest order term in divisor $2 x$ .

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

Step 13

Multiply the new quotient term by the divisor.

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

$\frac{45 x^{2}}{4}$

$\frac{135 x}{8}$

Step 14

The expression needs to be subtracted from the dividend, so change all the signs in $- \frac{45 x^{2}}{4} + \frac{135 x}{8}$

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

$\frac{45 x^{2}}{4}$

$\frac{135 x}{8}$

Step 15

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

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

$\frac{45 x^{2}}{4}$

$\frac{135 x}{8}$

$\frac{73 x}{8}$

Step 16

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

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

$\frac{45 x^{2}}{4}$

$\frac{135 x}{8}$

$\frac{73 x}{8}$

$12$

Step 17

Divide the highest order term in the dividend $\frac{73 x}{8}$ by the highest order term in divisor $2 x$ .

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$\frac{73}{16}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

$\frac{45 x^{2}}{4}$

$\frac{135 x}{8}$

$\frac{73 x}{8}$

$12$

Step 18

Multiply the new quotient term by the divisor.

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$\frac{73}{16}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

$\frac{45 x^{2}}{4}$

$\frac{135 x}{8}$

$\frac{73 x}{8}$

$12$

$\frac{73 x}{8}$

$\frac{219}{16}$

Step 19

The expression needs to be subtracted from the dividend, so change all the signs in $\frac{73 x}{8} - \frac{219}{16}$

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$\frac{73}{16}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

$\frac{45 x^{2}}{4}$

$\frac{135 x}{8}$

$\frac{73 x}{8}$

$12$

$\frac{73 x}{8}$

$\frac{219}{16}$

Step 20

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

$\frac{x^{3}}{2}$

$\frac{15 x^{2}}{4}$

$\frac{45 x}{8}$

$\frac{73}{16}$

$2 x$

$3$

$x^{4}$

$9 x^{3}$

$0 x^{2}$

$26 x$

$12$

$x^{4}$

$\frac{3 x^{3}}{2}$

$\frac{15 x^{3}}{2}$

$0 x^{2}$

$\frac{15 x^{3}}{2}$

$\frac{45 x^{2}}{4}$

$26 x$

$\frac{45 x^{2}}{4}$

$\frac{135 x}{8}$

$\frac{73 x}{8}$

$12$

$\frac{73 x}{8}$

$\frac{219}{16}$

$\frac{411}{16}$

Step 21

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

$\frac{x^{3}}{2} - \frac{15 x^{2}}{4} - \frac{45 x}{8} + \frac{73}{16} + \frac{411}{16 (2 x - 3)}$