[tex]c = \frac{1}{2b} + \frac{x}{b} [/tex]
[tex]c = \frac{1}{2b} + \frac{2x}{2b} [/tex]
[tex]c = \frac{1 + 2x}{2b} [/tex]
[tex]2bc = 1 + 2x[/tex]
[tex]b = \frac{1 + 2x}{2c} [/tex]
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[tex]mv = Th[/tex]
[tex]v = \frac{Th}{m} [/tex]
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[tex]2k = 7m + 5[/tex]
[tex]7m + 5 = 2k[/tex]
[tex]7m = 2k - 5[/tex]
[tex]m = \frac{2k - 5}{7} [/tex]
