Table of contents
- 0. Fundamental Concepts of Algebra3h 29m
- 1. Equations and Inequalities3h 27m
- 2. Graphs1h 43m
- 3. Functions & Graphs2h 17m
- 4. Polynomial Functions1h 54m
- 5. Rational Functions1h 23m
- 6. Exponential and Logarithmic Functions2h 28m
- 7. Measuring Angles40m
- 8. Trigonometric Functions on Right Triangles2h 5m
- 9. Unit Circle1h 19m
- 10. Graphing Trigonometric Functions1h 19m
- 11. Inverse Trigonometric Functions and Basic Trig Equations1h 41m
- 12. Trigonometric Identities 2h 34m
- 13. Non-Right Triangles1h 38m
- 14. Vectors2h 25m
- 15. Polar Equations2h 5m
- 16. Parametric Equations1h 6m
- 17. Graphing Complex Numbers1h 7m
- 18. Systems of Equations and Matrices3h 6m
- 19. Conic Sections2h 36m
- 20. Sequences, Series & Induction1h 15m
- 21. Combinatorics and Probability1h 45m
- 22. Limits & Continuity1h 49m
- 23. Intro to Derivatives & Area Under the Curve2h 9m
1. Equations and Inequalities
Complex Numbers
Struggling with Precalculus?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Find the sum. Express your answer in standard form. 5(4+7i)+6(3−2i)
A
7+5i
B
38+23i
C
2+47i
D
7+9i

1
First, distribute the 5 into the expression (4 + 7i). This means you multiply 5 by each term inside the parentheses: 5 * 4 and 5 * 7i.
Next, distribute the 6 into the expression (3 - 2i). This involves multiplying 6 by each term inside the parentheses: 6 * 3 and 6 * -2i.
After distributing, you will have two complex numbers. Add these two complex numbers together by combining the real parts and the imaginary parts separately.
Now, add the result from the previous step to the complex number (7 + 5i). Again, combine the real parts and the imaginary parts separately.
Finally, express the sum in standard form, which is a + bi, where a is the real part and b is the imaginary part.
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