Math Problem Statement

Solve each system of equations without graphing and show your reasoning. The system is: 2x + 3y = 7 and -2x + 4y = 14.

Solution

Let's solve the given system of equations step by step.

The system of equations is:

1) \ 2x + 3y &= 7 \\ 2) \ -2x + 4y &= 14 \end{aligned}$$ ### Step 1: Add the equations To eliminate $$x$$, add both equations: $$(2x + 3y) + (-2x + 4y) = 7 + 14$$ This simplifies to: $$0x + 7y = 21 \quad \Rightarrow \quad 7y = 21$$ ### Step 2: Solve for $$y$$ Divide both sides by 7: $$y = \frac{21}{7} = 3$$ ### Step 3: Substitute $$y = 3$$ into one of the original equations Now substitute $$y = 3$$ into the first equation $$2x + 3y = 7$$: $$2x + 3(3) = 7 \quad \Rightarrow \quad 2x + 9 = 7$$ ### Step 4: Solve for $$x$$ Subtract 9 from both sides: $$2x = 7 - 9 \quad \Rightarrow \quad 2x = -2$$ Divide by 2: $$x = \frac{-2}{2} = -1$$ ### Solution The solution to the system is: $$x = -1, \quad y = 3$$ ### Verification Let's substitute $$x = -1$$ and $$y = 3$$ into the second equation to check: $$-2(-1) + 4(3) = 2 + 12 = 14$$ This is true, so the solution is correct. --- Would you like further details on this solution? Here are some related questions for practice: 1. What is the elimination method and when is it useful? 2. How would the solution differ if both equations were dependent? 3. What if one of the equations was non-linear—how would you approach it? 4. Could substitution work here, and how would you apply it? 5. How do you check if a system of equations has no solution or infinite solutions? **Tip:** Always verify your solutions by substituting them back into the original equations to avoid mistakes.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Systems of Equations
Elimination Method

Formulas

Addition of equations to eliminate variables
Substitution of known values
Solving linear equations

Theorems

Elimination Method
Linear Equations

Suitable Grade Level

Grades 8-10