Math Is Fun Forum
Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2008-03-13 21:40:59
- tony123
- Member
- Registered: 2007-08-03
- Posts: 229
solve the system
solve the system
Offline
#2 2008-03-14 07:45:30
- JaneFairfax
- Member
- Registered: 2007-02-23
- Posts: 6,868
Re: solve the system
In the first equation, let X = 2x−y. Then you have
The LHS function is strictly decreasing, so there is only one solution, namely X = 1.
Substituting y = 2x−1 into the second equation yields
Now this function is strictly increasing, so the only solution is x = 0. Hence
Offline
Pages: 1