Question 989235
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*[tex \LARGE \ \ \ \ \ \ \ \ \ \ x\ +\ y\ =\ 20]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \frac{1}{x}\ +\ \frac{1}{y}\ =\ \frac{4}{15}]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ y\ =\ 20\ -\ x]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \frac{1}{x}\ +\ \frac{1}{20\ - x}\ =\ \frac{4}{15}]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \frac{20}{20x\ -\ x^2}\ =\ \frac{4}{15}]


Cross-multiply, collect like terms, and solve the resulting quadratic for *[tex \Large x].  The two roots will be the values of x and y that you need.

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AND
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One question per post.


John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it

*[tex \Large \ \
*[tex \LARGE \ \ \ \ \ \ \ \ \ \