Simplify (5-7i)^2

${(5 - 7 i)}^{2}$

Step 1

Rewrite ${(5 - 7 i)}^{2}$ as $(5 - 7 i) (5 - 7 i)$ .

$(5 - 7 i) (5 - 7 i)$

Step 2

Expand $(5 - 7 i) (5 - 7 i)$ using the FOIL Method.

Apply the distributive property.

$5 (5 - 7 i) - 7 i (5 - 7 i)$

Apply the distributive property.

$5 \cdot 5 + 5 (- 7 i) - 7 i (5 - 7 i)$

Apply the distributive property.

$5 \cdot 5 + 5 (- 7 i) - 7 i \cdot 5 - 7 i (- 7 i)$

Step 3

Simplify and combine like terms.

Simplify each term.

Multiply $5$ by $5$ .

$25 + 5 (- 7 i) - 7 i \cdot 5 - 7 i (- 7 i)$

Multiply $- 7$ by $5$ .

$25 - 35 i - 7 i \cdot 5 - 7 i (- 7 i)$

Multiply $5$ by $- 7$ .

$25 - 35 i - 35 i - 7 i (- 7 i)$

Multiply $- 7 i (- 7 i)$ .

Multiply $- 7$ by $- 7$ .

$25 - 35 i - 35 i + 49 i i$

Raise $i$ to the power of $1$ .

$25 - 35 i - 35 i + 49 (i^{1} i)$

Raise $i$ to the power of $1$ .

$25 - 35 i - 35 i + 49 (i^{1} i^{1})$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$25 - 35 i - 35 i + 49 i^{1 + 1}$

Add $1$ and $1$ .

$25 - 35 i - 35 i + 49 i^{2}$

Rewrite $i^{2}$ as $- 1$ .

$25 - 35 i - 35 i + 49 \cdot - 1$

Multiply $49$ by $- 1$ .

$25 - 35 i - 35 i - 49$

Subtract $49$ from $25$ .

$- 24 - 35 i - 35 i$

Subtract $35 i$ from $- 35 i$ .

$- 24 - 70 i$