Math Problem Statement
Solve the system of equations: 5x - 2y = 20 and 7x + 4y = 11.
Solution
To solve the given system of equations:
5x - 2y &= 20 \\ 7x + 4y &= 11 \end{aligned}$$ ### Step 1: Eliminate one variable We will use the elimination method. To eliminate $$y$$, we make the coefficients of $$y$$ in both equations equal. Multiply the first equation by 2 and the second equation by 1 (to match the $$y$$-coefficients): $$\begin{aligned} 2(5x - 2y) &= 2(20) \implies 10x - 4y = 40, \\ 1(7x + 4y) &= 1(11) \implies 7x + 4y = 11. \end{aligned}$$ ### Step 2: Add the two equations Adding the equations eliminates $$y$$: $$(10x - 4y) + (7x + 4y) = 40 + 11 \implies 17x = 51.$$ Solve for $$x$$: $$x = \frac{51}{17} = 3.$$ ### Step 3: Substitute $$x = 3$$ into one of the original equations Use the first equation $$5x - 2y = 20$$: $$5(3) - 2y = 20 \implies 15 - 2y = 20 \implies -2y = 5 \implies y = -\frac{5}{2}.$$ ### Final Answer: $$x = 3, \quad y = -\frac{5}{2}.$$ Would you like me to explain any step in further detail or solve it using a different method? --- Here are 5 related questions to deepen your understanding: 1. How can the substitution method be used to solve this system of equations? 2. What happens if you eliminate $$x$$ instead of $$y$$? 3. Can a system of equations have no solution or infinitely many solutions? How do we identify such cases? 4. How would graphing these two equations look, and where would the solution lie? 5. What are other examples of real-life problems modeled by linear systems? **Tip:** Always double-check your solution by substituting both $$x$$ and $$y$$ back into the original equations.Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Algebra
System of Equations
Elimination Method
Formulas
5x - 2y = 20
7x + 4y = 11
Theorems
Elimination method
Suitable Grade Level
Grades 7-9
Related Recommendation
Solving the System of Equations 2x - 7y = 20 and -3x - 7y = 5
Solve the System of Linear Equations: 20x - 6y = 44 and -7x - 3y = 5 using Elimination
Solving System of Linear Equations: x - 3y = -20 and 6x - 7y = -10
Solve System of Equations using Elimination: 2x + y = 20 and 6x - 5y = 12
Solving a System of Linear Equations Using Elimination: -5x + 2y = -11 and -x + 2y = -7