Finite Math Examples

${(x + 3)}^{8}$

Step 1

Pascal's Triangle can be displayed as such:

$1$

$1 - 1$

$1 - 2 - 1$

$\dots$

$1 - 6 - 15 - 20 - 15 - 6 - 1$

$1 - 7 - 21 - 35 - 35 - 21 - 7 - 1$

$1 - 8 - 28 - 56 - 70 - 56 - 28 - 8 - 1$

The triangle can be used to calculate the coefficients of the expansion of ${(a + b)}^{n}$ by taking the exponent $n$ and adding $1$ . The coefficients will correspond with line $n + 1$ of the triangle. For ${(x + 3)}^{8}$ , $n = 8$ so the coefficients of the expansion will correspond with line $9$ .

Step 2

The expansion follows the rule ${(a + b)}^{n} = c_{0} a^{n} b^{0} + c_{1} a^{n - 1} b^{1} + c_{n - 1} a^{1} b^{n - 1} + c_{n} a^{0} b^{n}$ . The values of the coefficients, from the triangle, are $1 - 8 - 28 - 56 - 70 - 56 - 28 - 8 - 1$ .

$1 a^{8} b^{0} + 8 a^{7} b + 28 a^{6} b^{2} + 56 a^{5} b^{3} + 70 a^{4} b^{4} + 56 a^{3} b^{5} + 28 a^{2} b^{6} + 8 a b^{7} + 1 a^{0} b^{8}$

Step 3

Substitute the actual values of $a$ $x$ and $b$ $3$ into the expression.

$1 {(x)}^{8} {(3)}^{0} + 8 {(x)}^{7} {(3)}^{1} + 28 {(x)}^{6} {(3)}^{2} + 56 {(x)}^{5} {(3)}^{3} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4

Simplify each term.

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Step 4.1

Multiply ${(x)}^{8}$ by $1$ .

${(x)}^{8} {(3)}^{0} + 8 {(x)}^{7} {(3)}^{1} + 28 {(x)}^{6} {(3)}^{2} + 56 {(x)}^{5} {(3)}^{3} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.2

Anything raised to $0$ is $1$ .

$x^{8} \cdot 1 + 8 {(x)}^{7} {(3)}^{1} + 28 {(x)}^{6} {(3)}^{2} + 56 {(x)}^{5} {(3)}^{3} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.3

Multiply $x^{8}$ by $1$ .

$x^{8} + 8 {(x)}^{7} {(3)}^{1} + 28 {(x)}^{6} {(3)}^{2} + 56 {(x)}^{5} {(3)}^{3} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.4

Evaluate the exponent.

$x^{8} + 8 x^{7} \cdot 3 + 28 {(x)}^{6} {(3)}^{2} + 56 {(x)}^{5} {(3)}^{3} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.5

Multiply $3$ by $8$ .

$x^{8} + 24 x^{7} + 28 {(x)}^{6} {(3)}^{2} + 56 {(x)}^{5} {(3)}^{3} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.6

Raise $3$ to the power of $2$ .

$x^{8} + 24 x^{7} + 28 x^{6} \cdot 9 + 56 {(x)}^{5} {(3)}^{3} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.7

Multiply $9$ by $28$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 56 {(x)}^{5} {(3)}^{3} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.8

Raise $3$ to the power of $3$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 56 x^{5} \cdot 27 + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.9

Multiply $27$ by $56$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 70 {(x)}^{4} {(3)}^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.10

Raise $3$ to the power of $4$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 70 x^{4} \cdot 81 + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.11

Multiply $81$ by $70$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 56 {(x)}^{3} {(3)}^{5} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.12

Raise $3$ to the power of $5$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 56 x^{3} \cdot 243 + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.13

Multiply $243$ by $56$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 28 {(x)}^{2} {(3)}^{6} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.14

Raise $3$ to the power of $6$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 28 x^{2} \cdot 729 + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.15

Multiply $729$ by $28$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 20412 x^{2} + 8 {(x)}^{1} {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.16

Simplify.

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 20412 x^{2} + 8 x {(3)}^{7} + 1 {(x)}^{0} {(3)}^{8}$

Step 4.17

Raise $3$ to the power of $7$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 20412 x^{2} + 8 x \cdot 2187 + 1 {(x)}^{0} {(3)}^{8}$

Step 4.18

Multiply $2187$ by $8$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 20412 x^{2} + 17496 x + 1 {(x)}^{0} {(3)}^{8}$

Step 4.19

Multiply ${(x)}^{0}$ by $1$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 20412 x^{2} + 17496 x + {(x)}^{0} {(3)}^{8}$

Step 4.20

Anything raised to $0$ is $1$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 20412 x^{2} + 17496 x + 1 {(3)}^{8}$

Step 4.21

Multiply ${(3)}^{8}$ by $1$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 20412 x^{2} + 17496 x + {(3)}^{8}$

Step 4.22

Raise $3$ to the power of $8$ .

$x^{8} + 24 x^{7} + 252 x^{6} + 1512 x^{5} + 5670 x^{4} + 13608 x^{3} + 20412 x^{2} + 17496 x + 6561$