Math Problem Statement

solve the system using elimination 4x + 8y = 12 3x-8y = 9

Solution

We are given the following system of equations:

  1. 4x+8y=124x + 8y = 12
  2. 3x8y=93x - 8y = 9

We will use the elimination method to solve this system.

Step 1: Eliminate one of the variables

In this case, the coefficients of yy are opposites (+8 and -8), so we can eliminate yy by adding the two equations together.

(4x+8y)+(3x8y)=12+9(4x + 8y) + (3x - 8y) = 12 + 9

Simplify:

4x+3x+8y8y=214x + 3x + 8y - 8y = 21 7x=217x = 21

Step 2: Solve for xx

Now, solve for xx:

x=217x = \frac{21}{7} x=3x = 3

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

We will substitute x=3x = 3 into the first equation 4x+8y=124x + 8y = 12:

4(3)+8y=124(3) + 8y = 12 12+8y=1212 + 8y = 12

Step 4: Solve for yy

Now, subtract 12 from both sides:

8y=08y = 0

Finally, divide by 8:

y=0y = 0

Solution:

The solution to the system is:

x=3,y=0x = 3, \quad y = 0


Would you like more details or have any questions?

Here are some related questions for further exploration:

  1. How would you solve a system with fractions using elimination?
  2. Can the elimination method be used with non-linear systems?
  3. What is the graphical interpretation of the solution to a system of linear equations?
  4. How does the substitution method compare to the elimination method?
  5. What would happen if the two lines in this system were parallel?

Tip: When using the elimination method, always look for coefficients that are the same or additive inverses to eliminate a variable easily.

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Math Problem Analysis

Mathematical Concepts

Algebra
Systems of Linear Equations
Elimination Method

Formulas

Adding or subtracting equations to eliminate a variable
Substitution of a known variable into an equation

Theorems

Properties of Equality
Addition and Subtraction Properties of Equations

Suitable Grade Level

Grades 8-10