Math Problem Statement

Solve the system of linear equations without graphing: 5x + 4y = 8 and 10x - 4y = 46.

Solution

The system of linear equations to solve is:

5x+4y=8(Equation 1)5x + 4y = 8 \quad \text{(Equation 1)} 10x4y=46(Equation 2)10x - 4y = 46 \quad \text{(Equation 2)}

Step 1: Add the equations

To eliminate yy, add both equations:

(5x+4y)+(10x4y)=8+46(5x + 4y) + (10x - 4y) = 8 + 46

Simplifying:

5x+10x+4y4y=545x + 10x + 4y - 4y = 54

15x=5415x = 54

Step 2: Solve for xx

Now, solve for xx by dividing both sides by 15:

x=5415=185x = \frac{54}{15} = \frac{18}{5}

Step 3: Substitute xx into one of the original equations

Substitute x=185x = \frac{18}{5} into Equation 1:

5(185)+4y=85\left(\frac{18}{5}\right) + 4y = 8

This simplifies to:

18+4y=818 + 4y = 8

Step 4: Solve for yy

Now, solve for yy:

4y=8184y = 8 - 18

4y=104y = -10

y=104=52y = \frac{-10}{4} = \frac{-5}{2}

Final Answer:

The solution to the system is:

x=185,y=52x = \frac{18}{5}, \quad y = \frac{-5}{2}

Would you like further details or have any questions?

Here are some related questions to consider:

  1. How would the method change if you wanted to use substitution instead of addition?
  2. What are the advantages of solving by elimination in this case?
  3. Could the solution have been found using matrices? If so, how?
  4. What does the geometric interpretation of this solution look like?
  5. How would you verify the solution?

Tip: When working with systems of equations, always check your solutions by substituting back into the original equations.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Linear Equations
Systems of Equations
Elimination Method

Formulas

Addition of equations: (a + b = c) + (d - b = e)
Solving for a variable: ax = b -> x = b/a

Theorems

Elimination Method

Suitable Grade Level

Grades 8-10