Question

question
simplify the expression to a + bi form:
(-7 + 7i)(-10 - 9i)

Explanation:

Step1: Apply distributive property (FOIL)

$(-7)(-10) + (-7)(-9i) + (7i)(-10) + (7i)(-9i)$

Step2: Calculate each term

$70 + 63i - 70i - 63i^2$

Step3: Substitute $i^2=-1$

$70 + 63i - 70i - 63(-1)$

Step4: Simplify real and imaginary parts

$70 + 63 + (63i - 70i)$
$133 - 7i$

Answer:

$133 - 7i$