Math Problem Statement

Solve using elimination.

–2x + 3y = –2 –4x + 7y = –10

Solution

To solve the system of equations using the elimination method, we aim to eliminate one variable by making its coefficients equal in both equations. The given system of equations is:

  1. 2x+3y=2-2x + 3y = -2
  2. 4x+7y=10-4x + 7y = -10

Step 1: Make the coefficients of xx equal

To eliminate xx, we can multiply the first equation by 2, so that the coefficient of xx in the first equation matches the coefficient in the second equation:

2(2x+3y)=2(2)2(-2x + 3y) = 2(-2)

4x+6y=4-4x + 6y = -4

Now the system becomes:

1.4x+6y=41'. \, -4x + 6y = -4 2.4x+7y=102. \, -4x + 7y = -10

Step 2: Subtract one equation from the other

Subtract equation 11' from equation 22:

(4x+7y)(4x+6y)=10(4)(-4x + 7y) - (-4x + 6y) = -10 - (-4)

Simplify:

y=6y = -6

Step 3: Substitute y=6y = -6 into one of the original equations

Substitute y=6y = -6 into the first equation, 2x+3y=2-2x + 3y = -2:

2x+3(6)=2-2x + 3(-6) = -2

2x18=2-2x - 18 = -2

2x=16-2x = 16

x=8x = -8

Final Solution:

The solution to the system of equations is:

x=8,y=6x = -8, \, y = -6

Verification:

Substitute x=8x = -8 and y=6y = -6 into both equations to ensure they are satisfied:

  1. 2(8)+3(6)=1618=2-2(-8) + 3(-6) = 16 - 18 = -2
  2. 4(8)+7(6)=3242=10-4(-8) + 7(-6) = 32 - 42 = -10

The solution is correct.


Do you have any questions, or would you like further details on any step?

Here are 5 related questions to deepen your understanding:

  1. How would you solve this system using the substitution method instead?
  2. What happens if both variables were eliminated during elimination?
  3. How can you identify inconsistent systems using elimination?
  4. Can elimination work efficiently with three equations and three variables?
  5. How does elimination compare to graphing methods for solving systems?

Tip: Always verify your solution by substituting back into the original equations.

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Math Problem Analysis

Mathematical Concepts

Systems of Equations
Elimination Method

Formulas

Elimination method steps: 1) Make coefficients equal, 2) Subtract equations, 3) Solve for remaining variable

Theorems

Elimination method for solving systems of linear equations

Suitable Grade Level

Grades 9-11