Question 1023045
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*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 0.10d\ +\ 0.05n\ =\ 3.15]


is correct, but you are given that *[tex \Large n\ =\ d\ -\ 9] so:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 0.10d\ +\ 0.05(d\ -\ 9)\ =\ 3.15].


Now solve for *[tex \Large d].


Note that


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 10d\ +\ 5(d\ -\ 9)\ =\ 315]


has the same solution set but is less confusing and less mistake-prone because of the elimination of the decimals.


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

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

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