# Math Help - solve

1. ## solve

2. Originally Posted by rj2001
Here

3. Yes, the equation does not has solution, that is all

4. in retrospect, i'm thinking we could divide by z - 9 to get the equation z - 7 = 2 and avoid that annoying quadratic. apparently when i did this problem i was concerned about z - 9 being 0, but now i see that that can't be the case, since the original fractions wouldn't be valid in the first place

5. Yeah i agree, it simply doesnt have a solution.

6. Originally Posted by janvdl
Yeah i agree, it simply doesnt have a solution.
right, because z can't be 9

7. $z\neq 9$.
Then $\displaystyle \frac{z-7}{z-9}=\frac{2}{z-9}\Leftrightarrow \frac{z-7}{z-9}-\frac{2}{z-9}=0\Leftrightarrow \frac{z-9}{z-9}=0\Leftrightarrow 1=0$, false!