(-3+5i)(-5+7i)

2 min read Jun 16, 2024
(-3+5i)(-5+7i)

Multiplying Complex Numbers: (-3 + 5i)(-5 + 7i)

This article will guide you through multiplying two complex numbers: (-3 + 5i) and (-5 + 7i).

Understanding Complex Numbers

Complex numbers are numbers that can be expressed in the form a + bi, where a and b are real numbers and i is the imaginary unit, defined as the square root of -1.

Multiplication Process

Multiplying complex numbers is similar to multiplying binomials. We use the distributive property (or FOIL method) to expand the product:

(-3 + 5i)(-5 + 7i) = (-3)(-5) + (-3)(7i) + (5i)(-5) + (5i)(7i)

Simplifying the terms:

= 15 - 21i - 25i + 35i²

Dealing with i²

Recall that i² = -1. Substituting this value into our equation:

= 15 - 21i - 25i + 35(-1)

Combining Real and Imaginary Terms

Now, we group the real terms and the imaginary terms:

= (15 - 35) + (-21 - 25)i

Final Result

Simplifying the equation, we get the final result:

= -20 - 46i

Therefore, the product of (-3 + 5i) and (-5 + 7i) is -20 - 46i.

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