Practice question · Put in order
Order the steps of solving 'x + y = 5, 2x + y = 8' by elimination.
- This gives x = 3
- Solve to get y = 2
- Substitute x = 3 into x + y = 5
- Subtract the first equation from the second to cancel y
Hints
- Elimination first removes one variable by combining equations.
- Once one variable is known, back-substitute to find the other.
Show the answer
- Subtract the first equation from the second to cancel y
- This gives x = 3
- Substitute x = 3 into x + y = 5
- Solve to get y = 2
Why
Subtracting cancels y because both equations have +y: (2x+y)-(x+y) = x = 3. Then substitution recovers y = 2. Eliminate, then back-substitute.
Practise Systems of Linear Equations
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