Solve System of Equations: 2x + y = 8, x - y = 1

Published on October 7, 2024

Algebra

Solve the system of equations 2x + y = 8 and x - y = 1. The solution is x = 3 and y = 2.

Question

Solve the system of equations: 2x + y = 8 x - y = 1

Answer

Here’s how to solve the system of equations step-by-step:
1. Elimination Method
  • Notice that the ‘y’ coefficients have opposite signs. This makes it easy to eliminate ‘y’ by adding the equations together.
  • Add the equations:
    (2x + y) + (x - y) = 8 + 1
  • Simplify:
    3x = 9
  • Solve for ‘x’:
    x = 3
2. Substitution
  • Now that we know x = 3, substitute it into either of the original equations to solve for ‘y’. Let’s use the first equation:
    2(3) + y = 8
  • Simplify:
    6 + y = 8
  • Solve for ‘y’:
    y = 2
Answer:
The solution to the system of equations is x = 3 and y = 2. This can also be written as the ordered pair (3, 2).