<s>[INST] How to solve this simple equation $\frac{46}{y} + y = 25$? How do I solve this simple equation?  $\frac{46}{y} + y = 25$
I know that the answer is $2$, but how do I arrive at that? 
 [/INST] Multiply both sides by $y$ and you get
$$46 + y^2 = 25y$$
$$\Leftrightarrow 0 = y^2 -25y + 46$$
Now calculating the discriminant $D = (-25)^2 -4\cdot 46 = 625-184 = 441 = 21^2$ gives
$$y = \frac{25 \pm \sqrt{21^2}}{2}$$
So $y = \frac{25+21}{2} = 23$ or $y = \frac{25-21}{2} = 2$.
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