Solving simultaneous equations.
This problem has been driving me crazy: If 2x - y = 9 and 3x + 4y = -14, then x = ? and y = ?
I keep getting y = -9 and x = 7.33 by doing this:
2x - y = 9 -> 2x - 9 = y -> 2(0) - 9 = y -> -9 = y
3x + 4(-9) = -14 -> 3x + -36 = -14 -> 3x = 22 -> x = 7.33
I know these are wrong, though. Would anyone be able to tell me what's wrong?
Thanks in advance!
Re: Basic algebra problem
you cannot assume that x=0,because if it isn't it is going to give you wrong answers.
you can try doing something like this:
we substitute into the second equation:
can you find y now?