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
18. Systems of Equations and Matrices
Two Variable Systems of Linear Equations
Struggling with Precalculus?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Use substitution to solve the following system of linear equations.
4x+2y=7
x+5y=4
A
(21,23)
B
(23,21)
C
(−32,31)
D
(−31,32)

1
Start by identifying the two equations in the system: Equation 1 is 4x + 2y = 7 and Equation 2 is x + 5y = 4.
Choose one of the equations to solve for one variable in terms of the other. Let's solve Equation 2 for x: x = 4 - 5y.
Substitute the expression for x from Step 2 into Equation 1. This gives: 4(4 - 5y) + 2y = 7.
Simplify the equation from Step 3 by distributing and combining like terms: 16 - 20y + 2y = 7.
Solve the simplified equation for y. Once you have the value of y, substitute it back into the expression for x from Step 2 to find the value of x.
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