Math Problem Statement

the answer

The following system of equations cannot be immediately solved using elimination. -6x + 4y = 26 5x + 2y = 37 How can it be changed so that adding the equations will eliminate one of the variables?

Solution

The system of equations given in the image is:

6x+4y=26-6x + 4y = 26 5x+2y=375x + 2y = 37

To eliminate one of the variables using the elimination method, we need to manipulate the equations so that either the xx-terms or the yy-terms become opposites.

Step 1: Focus on the coefficients of either xx or yy.

Let's focus on eliminating yy, since the coefficients of yy are 44 and 22. To eliminate yy, we want to make the coefficients of yy in both equations equal but with opposite signs.

Step 2: Make the yy-terms opposites.

To do this, we can multiply the second equation by 2-2, so that the coefficient of yy in the second equation becomes 4-4, which is the opposite of the coefficient of yy in the first equation.

Multiplying the second equation by 2-2:

2(5x+2y=37)    10x4y=74-2(5x + 2y = 37) \implies -10x - 4y = -74

Now, the system becomes:

6x+4y=26-6x + 4y = 26 10x4y=74-10x - 4y = -74

Step 3: Add the equations.

Now, add the two equations together:

(6x+4y)+(10x4y)=26+(74)(-6x + 4y) + (-10x - 4y) = 26 + (-74)

This simplifies to:

16x=48-16x = -48

Solving for xx:

x=4816=3x = \frac{-48}{-16} = 3

Correct Answer:

The operation needed to eliminate one of the variables is Option C: Multiply the second equation by -2.

Would you like further details on solving the full system, or have any other questions?

Here are 5 related questions to explore:

  1. How can we solve for yy after finding x=3x = 3?
  2. What would happen if we tried eliminating xx instead of yy?
  3. Why is multiplying one of the equations necessary for elimination?
  4. Can you always use the elimination method, or are there cases where it doesn't work well?
  5. How does elimination compare to the substitution method?

Tip: When using the elimination method, always focus on which variable can be easily eliminated by adjusting the coefficients.

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Math Problem Analysis

Mathematical Concepts

Algebra
System of Linear Equations
Elimination Method

Formulas

Ax + By = C
Elimination: Adjust coefficients to cancel one variable

Theorems

Linear Equation Elimination Method

Suitable Grade Level

Grade 9-10