Math Problem Statement

–9x + 7y = 7 6x − 7y = 14

Solution

We are given the system of linear equations:

9x+7y=7(1)-9x + 7y = 7 \quad \text{(1)} 6x7y=14(2)6x - 7y = 14 \quad \text{(2)}

Let's solve this system using the elimination method.

Step 1: Add the two equations

Notice that the 7y7y terms have opposite signs, so adding the equations will eliminate yy.

(9x+7y)+(6x7y)=7+14(-9x + 7y) + (6x - 7y) = 7 + 14

Simplifying this:

9x+6x=21-9x + 6x = 21 3x=21-3x = 21

Step 2: Solve for xx

Divide both sides by 3-3:

x=213=7x = \frac{21}{-3} = -7

Step 3: Substitute x=7x = -7 into one of the original equations

Substitute into equation (2) to solve for yy:

6(7)7y=146(-7) - 7y = 14 427y=14-42 - 7y = 14

Add 4242 to both sides:

7y=14+42-7y = 14 + 42 7y=56-7y = 56

Step 4: Solve for yy

Divide both sides by 7-7:

y=567=8y = \frac{56}{-7} = -8

Final Solution:

The solution to the system of equations is: x=7,y=8x = -7, \quad y = -8

Would you like more details or have any questions?


Here are 5 related questions:

  1. How would you solve this system using substitution?
  2. Can you verify the solution by substituting into both original equations?
  3. What are the general steps in the elimination method for solving systems of equations?
  4. How does this method differ from solving systems graphically?
  5. What is the geometric interpretation of solving a system of two linear equations?

Tip: When using the elimination method, look for variables with coefficients that can easily cancel out!

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Math Problem Analysis

Mathematical Concepts

Algebra
Linear Equations
Systems of Equations
Elimination Method

Formulas

Linear equation in two variables: ax + by = c
Elimination method: Add or subtract equations to eliminate one variable

Theorems

Elimination Method for Solving Systems of Linear Equations

Suitable Grade Level

Grades 8-10