Math Problem Statement

x-2y+4z=3 x+3y-2z=6 x-4y+3z=-5 Solve the systems of equations

Solution

We are given the following system of equations:

  1. x2y+4z=3x - 2y + 4z = 3
  2. x+3y2z=6x + 3y - 2z = 6
  3. x4y+3z=5x - 4y + 3z = -5

To solve this system of equations, we will use the substitution method or elimination method. Let's use the elimination method for this case.

Step 1: Eliminate one variable

First, we'll eliminate xx by subtracting the first equation from the second equation and subtracting the first equation from the third equation.

Subtract equation 1 from equation 2:

(x+3y2z)(x2y+4z)=63(x + 3y - 2z) - (x - 2y + 4z) = 6 - 3 Simplifying: xx+3y+2y2z4z=3x - x + 3y + 2y - 2z - 4z = 3 5y6z=3(Equation 4)5y - 6z = 3 \quad \text{(Equation 4)}

Subtract equation 1 from equation 3:

(x4y+3z)(x2y+4z)=53(x - 4y + 3z) - (x - 2y + 4z) = -5 - 3 Simplifying: xx4y+2y+3z4z=8x - x - 4y + 2y + 3z - 4z = -8 2yz=8(Equation 5)-2y - z = -8 \quad \text{(Equation 5)}

Step 2: Solve the new system of two equations

Now we have the following system of two equations:

  1. 5y6z=35y - 6z = 3
  2. 2yz=8-2y - z = -8

Solve for yy in terms of zz from equation 5:

2yz=82y=z8y=8z2-2y - z = -8 \quad \Rightarrow \quad -2y = z - 8 \quad \Rightarrow \quad y = \frac{8 - z}{2}

Substitute y=8z2y = \frac{8 - z}{2} into equation 4:

Substitute into 5y6z=35y - 6z = 3: 5(8z2)6z=35 \left( \frac{8 - z}{2} \right) - 6z = 3 Simplifying: 5(8z)26z=3\frac{5(8 - z)}{2} - 6z = 3 405z26z=3\frac{40 - 5z}{2} - 6z = 3 Multiply everything by 2 to clear the fraction: 405z12z=640 - 5z - 12z = 6 4017z=640 - 17z = 6 17z=640-17z = 6 - 40 17z=34-17z = -34 z=2z = 2

Step 3: Solve for yy

Substitute z=2z = 2 back into y=8z2y = \frac{8 - z}{2}: y=822=62=3y = \frac{8 - 2}{2} = \frac{6}{2} = 3

Step 4: Solve for xx

Now that we know y=3y = 3 and z=2z = 2, substitute these values into one of the original equations. Let's use the first equation x2y+4z=3x - 2y + 4z = 3: x2(3)+4(2)=3x - 2(3) + 4(2) = 3 x6+8=3x - 6 + 8 = 3 x+2=3x + 2 = 3 x=1x = 1

Final Solution:

The solution to the system of equations is: x=1,y=3,z=2x = 1, \quad y = 3, \quad z = 2

Would you like a detailed explanation of any step, or do you have other questions?


Here are some related questions that might help deepen your understanding:

  1. How do you apply the substitution method to solve a system of linear equations?
  2. What is the difference between the elimination method and substitution method in solving systems of equations?
  3. How do you check the solution to a system of linear equations?
  4. What happens if the system of equations has no solution or infinite solutions?
  5. How can matrices be used to solve a system of linear equations?

Tip: When solving systems of equations, always check if the variables in the equations are independent and if the system has a unique solution, infinitely many solutions, or no solution at all!

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Math Problem Analysis

Mathematical Concepts

Linear Systems
Elimination Method
Substitution Method

Formulas

Substitution Method
Elimination Method

Theorems

Systems of Linear Equations

Suitable Grade Level

Grades 9-11