Math Problem Statement

x1 +2x2 = -1, 4x1 +5x2 = -10 Find the solution to the system of equations. (x1, x2) =

Solution

We are given the system of linear equations:

x1+2x2=1(1)x_1 + 2x_2 = -1 \quad (1) 4x1+5x2=10(2)4x_1 + 5x_2 = -10 \quad (2)

To solve this, we'll use the substitution or elimination method. Let's proceed with the elimination method.

Step 1: Eliminate x1x_1

Multiply equation (1) by 4 to align the coefficients of x1x_1:

4(x1+2x2)=4(1)4(x_1 + 2x_2) = 4(-1) 4x1+8x2=4(3)4x_1 + 8x_2 = -4 \quad (3)

Now subtract equation (2) from equation (3):

(4x1+8x2)(4x1+5x2)=4(10)(4x_1 + 8x_2) - (4x_1 + 5x_2) = -4 - (-10) (4x14x1)+(8x25x2)=4+10(4x_1 - 4x_1) + (8x_2 - 5x_2) = -4 + 10 3x2=63x_2 = 6

Step 2: Solve for x2x_2

x2=63=2x_2 = \frac{6}{3} = 2

Step 3: Substitute x2=2x_2 = 2 into equation (1)

Substitute x2=2x_2 = 2 into equation (1):

x1+2(2)=1x_1 + 2(2) = -1 x1+4=1x_1 + 4 = -1 x1=14=5x_1 = -1 - 4 = -5

Final Solution:

The solution to the system of equations is:

(x1,x2)=(5,2)(x_1, x_2) = (-5, 2)

Do you have any questions or need further details?

Here are some related questions to explore:

  1. How would you solve the system using substitution instead of elimination?
  2. Can the determinant method (Cramer's rule) be used to solve this system?
  3. How do you graphically represent this system of equations?
  4. What happens if the system has no solutions or infinite solutions?
  5. How can matrix methods (e.g., Gaussian elimination) solve larger systems of equations?

Tip: When using elimination, always try to align coefficients by multiplication to simplify cancellation of variables.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linear Algebra
System of Linear Equations
Elimination Method

Formulas

Linear equation: ax + by = c
Elimination method

Theorems

Linear combination
Fundamental theorem of algebra (in context of systems of equations)

Suitable Grade Level

Grades 9-11