Simplifying Complex Expressions: (1+7i)(9+3i)-(4+2i)
This article will guide you through the process of simplifying the complex expression: (1+7i)(9+3i)-(4+2i).
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 (i² = -1).
Steps to Simplify the Expression
-
Expand the product:
- (1+7i)(9+3i) = 1(9) + 1(3i) + 7i(9) + 7i(3i)
- = 9 + 3i + 63i + 21i²
- = 9 + 66i + 21(-1) (Since i² = -1)
- = -12 + 66i
-
Combine the expanded product with the remaining term:
- (-12 + 66i) - (4 + 2i)
- = -12 - 4 + 66i - 2i
- = -16 + 64i
Final Result
Therefore, the simplified form of the expression (1+7i)(9+3i)-(4+2i) is -16 + 64i.