Systems of Equations Math Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

hard
Solve the system: 2x+3y=122x + 3y = 12 and xโˆ’y=1x - y = 1.

Solution

  1. 1
    Step 1: From the second equation, express xx in terms of yy: x=y+1x = y + 1.
  2. 2
    Step 2: Substitute into the first equation: 2(y+1)+3y=122(y + 1) + 3y = 12, so 2y+2+3y=122y + 2 + 3y = 12.
  3. 3
    Step 3: Combine like terms: 5y+2=125y + 2 = 12, so 5y=105y = 10 and y=2y = 2.
  4. 4
    Step 4: Back-substitute: x=2+1=3x = 2 + 1 = 3. Check: 2(3)+3(2)=122(3) + 3(2) = 12 โœ“ and 3โˆ’2=13 - 2 = 1 โœ“

Answer

x=3,y=2x = 3, \quad y = 2
Isolate one variable in the simpler equation and substitute into the other. This elimination-by-substitution approach works well when one equation can be easily solved for a single variable.

About Systems of Equations

Two or more equations sharing the same variables, where the solution must satisfy all equations simultaneously.

Learn more about Systems of Equations โ†’

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