Question

Express (7 + 5i) (7 - 5i) in the form of a + in
________________⚫_______________

Answer 1

$\huge\mathfrak{Hola\: Mate}$

$\huge\bold{Solution}$

We have,

(7 + 5i)(7 - 5i)

= 7 × 7 × 7(-5i) + 5i × 7 + 5i(-5i)

= 49 - 35i + 35i - 25i²

= 49 + 25 => 74

= 74 + 0i

= a + ib

Where, a = 74 and b = 0

Hope it helps you out✔✔

Answer 2

Answer:

74 + 0 i

Step-by-step explanation:

Given: (7 + 5i)(7 - 5i)

= 7 * 7 + 7 * (-5i) + (5i) * 7 + (5i) * (-5i)

= 49 - 35i + 35i - 25i²

= 49 - 25(-1) [∴ i² = -1]

= 49 + 25

= 74

= 74 + 0

= 74 + 0 i [Real and Imaginary part]

Hope it helps!