Mathematics Grade 11 15 min

Add three or more numbers with four or more digits - word problems

Add three or more numbers with four or more digits - word problems

Tutorial Preview

1

Introduction & Learning Objectives

Learning Objectives Translate a multi-step word problem into an expression involving the sum of three or more complex numbers. Accurately add the real and imaginary components of complex numbers, where each component is a number with four or more digits. Calculate the total impedance of a series AC circuit by summing the complex impedances of its components. Determine the resultant vector by summing multiple vectors represented as complex numbers. Interpret the real and imaginary parts of a final complex number sum in the context of a given real-world scenario. Verify the solution to a complex number addition problem by checking the sums of the real and imaginary parts independently. How do engineers calculate the total electrical effect of multiple large industrial machines...
2

Key Concepts & Vocabulary

TermDefinitionExample Complex NumberA number of the form z = a + bi, where 'a' is the real part, 'b' is the imaginary part, and 'i' is the imaginary unit (i² = -1).The complex number z = 4500 + 2150i has a real part of 4500 and an imaginary part of 2150. Real Part (Re(z))The component of a complex number that does not have 'i' as a coefficient. It is represented on the horizontal axis of the complex plane.For z = 8910 - 3456i, the real part is Re(z) = 8910. Imaginary Part (Im(z))The real number coefficient of the imaginary unit 'i'. It is represented on the vertical axis of the complex plane.For z = 8910 - 3456i, the imaginary part is Im(z) = -3456. Complex Plane (Argand Diagram)A two-dimensional coordinate plane where the horizontal axis...
3

Core Formulas

Addition of Complex Numbers (a + bi) + (c + di) = (a + c) + (b + d)i To add two complex numbers, add the real parts together and add the imaginary parts together separately. The structure of the complex number is maintained. Summation of Multiple Complex Numbers \sum_{k=1}^{n} (a_k + b_k i) = (\sum_{k=1}^{n} a_k) + (\sum_{k=1}^{n} b_k)i To add three or more complex numbers, sum all the real parts to get the final real part, and sum all the imaginary parts to get the final imaginary part.

4 more steps in this tutorial

Sign up free to access the complete tutorial with worked examples and practice.

Sign Up Free to Continue

Sample Practice Questions

Challenging
A drone's final position is given by the vector sum D_final = 8250 + 3150i. This was the result of four displacements. Three of the displacements were d₁ = 2100 + 1500i, d₂ = 4500 - 1200i, and d₄ = 1250 + 850i. What was the third displacement, d₃?
A.400 + 2000i
B.400 + 2000i
C.16100 + 4300i
D.-400 - 2000i
Challenging
Three impedances in a circuit are Z₁ = 2500 + 4000j, Z₂ = 3500 + 1500j, and Z₃ = k - 2500j, where k is a real number. For what value of k will the total impedance have an imaginary part of exactly 5000j?
A.k can be any real number.
B.k = 5000
C.k = 3000
D.k = -2000
Challenging
A student adds three impedances Z₁=2000+3000j, Z₂=4000+5000j, and Z₃=1000+2000j. They report a total of Z_total = 11000 + 8000j. They made the common pitfall error of adding the real part of one number to the imaginary part of another. Which specific error leads to their result?
A.They calculated (2000+4000+1000) + (3000+5000+2000)j, but swapped the final totals.
B.They calculated (2000+5000+1000) + (3000+4000+2000)j.
C.They calculated (2000+3000) + (4000+5000) + (1000+2000)j.
D.They added Z₁'s real part to Z₂'s imaginary part, and Z₂'s real part to Z₃'s imaginary part.

Want to practice and check your answers?

Sign up to access all questions with instant feedback, explanations, and progress tracking.

Start Practicing Free

More from Complex numbers

Ready to find your learning gaps?

Take a free diagnostic test and get a personalized learning plan in minutes.