What is the solution to log5(10x-1)=log5(9x=7)

1 answer:

4 0

$Domain:\\\\10x-1 > 0\ and\ 9x+7 > 0\\\\10x > 1\ and\ 9x > -7\\\\x > \dfrac{1}{10}\ and\ x > -\dfrac{7}{9}\Rightarrow x > \dfrac{1}{10}\\\\D=\left\{x|x > \dfrac{1}{10}\right\}\\\\\log_5(10x-1)=\log_5(9x+7)\iff10x-1=9x+7\qquad\text{add 1 to both sides}\\\\10x=9x+8\qquad\text{subtract 9x from both sides}\\\\x=8\in D\\\\Answer:\ \boxed{x=8}$

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(50Pts) When using the vertical method to multiply polynomials, your like terms must be lined up in ____________.

vaieri [72.5K]

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3 years ago

The rate of change in sales for Garmin from 2008 through 2013 can be modeled by

Zina [86]

Answer:

a) The model for the sales of Garmin is represented by $S(t) = -\frac{81}{2500}\cdot t^{3} + \frac{267}{250}\cdot t^{2} - 11.9\cdot t + 47.112$ .

b) The average sales of Garmin from 2008 through 2013 were $ 2.5 billion.

Step-by-step explanation:

a) The model for the sales of Garmin is obtained by integration:

$S(t) = -0.0972\int {t^{2}} \, dt + 2.136\int {t}\,dt -11.9 \int\,dt$

$S(t) = -\frac{81}{2500}\cdot t^{3} + \frac{267}{250}\cdot t^{2} - 11.9\cdot t + C$ (1)

Where $C$ is the integration constant.

If we know that $t = 9$ and $S(t) = 2.9$ , then the model for the sales of Garmin is:

$-\frac{81}{2500} \cdot 9^{3} + \frac{267}{250}\cdot 9^{2}-11.9\cdot (9) + C = 2.9$

$C = 47.112$

The model for the sales of Garmin is represented by $S(t) = -\frac{81}{2500}\cdot t^{3} + \frac{267}{250}\cdot t^{2} - 11.9\cdot t + 47.112$ .

b) The average sales of the Garmin from 2008 through 2013 ( $\bar{S}$ ) is determined by the integral form of the definition of average, this is:

$\bar{S} = \frac{1}{13 - 8} \cdot \int\limits^{13}_{8} {S(t)} \, dt$ (2)

$\bar S = \frac{1}{5}\cdot \int\limits^{13}_{8} {\left[-\frac{81}{2500}\cdot t^{3} + \frac{267}{250}\cdot t^{2}-11.9\cdot t + 47.112 \right]} \, dt$

$\bar S = \frac{1}{5}\cdot \left[-\frac{81}{10000}\cdot (13^{4}-8^{4}) +\frac{89}{250}\cdot (13^{3}-8^{3}) -\frac{119}{20}\cdot (13^{2}-8^{2}) +47.112\cdot (13-8) \right]$ $\bar{S} = \frac{1}{5}\cdot (-198.167+599.86-624.75+235.56)$