Example

Determining Whether Ordered Pairs are Solutions of {xy=1,  2xy=5}\{x - y = -1,\; 2x - y = -5\}

Determine whether each ordered pair is a solution to the system {xy=1,  2xy=5}\{x - y = -1,\; 2x - y = -5\}

ⓐ Testing (2,1)(-2, -1): Substitute x=2x = -2 and y=1y = -1 into both equations.

  • First equation: 2(1)=2+1=1-2 - (-1) = -2 + 1 = -1. Since 1=1-1 = -1 is true, the first equation is satisfied.
  • Second equation: 2(2)(1)=4+1=32(-2) - (-1) = -4 + 1 = -3. Since 35-3 \neq -5 is false, the second equation is not satisfied.

Because (2,1)(-2, -1) does not make both equations true, it is not a solution.

ⓑ Testing (4,3)(-4, -3): Substitute x=4x = -4 and y=3y = -3 into both equations.

  • First equation: 4(3)=4+3=1-4 - (-3) = -4 + 3 = -1. Since 1=1-1 = -1 is true, the first equation is satisfied.
  • Second equation: 2(4)(3)=8+3=52(-4) - (-3) = -8 + 3 = -5. Since 5=5-5 = -5 is true, the second equation is also satisfied.

Because (4,3)(-4, -3) makes both equations true, it is a solution of the system.

Image 0

0

1

Updated 2026-04-24

Contributors are:

Who are from:

Tags

OpenStax

Elementary Algebra @ OpenStax

Ch.5 Systems of Linear Equations - Elementary Algebra @ OpenStax

Algebra

Math

Prealgebra

Intermediate Algebra @ OpenStax

Ch.4 Systems of Linear Equations - Intermediate Algebra @ OpenStax

Related
Learn After