For simple interest
i=prn
where i= interest p=amount invested, r=rate n=time period
i= 970*4 and 1/4 * 2
i= $8245<span />
Answer:
![\int \:3\cdot \frac{x}{\left(x-1\right)^2}dx=3\left(\ln \left|x-1\right|-\frac{1}{x-1}\right)+C](https://tex.z-dn.net/?f=%5Cint%20%5C%3A3%5Ccdot%20%5Cfrac%7Bx%7D%7B%5Cleft%28x-1%5Cright%29%5E2%7Ddx%3D3%5Cleft%28%5Cln%20%5Cleft%7Cx-1%5Cright%7C-%5Cfrac%7B1%7D%7Bx-1%7D%5Cright%29%2BC)
Step-by-step explanation:
Given
![\int \:\:3\cdot \frac{x}{\left(x-1\right)^2}dx](https://tex.z-dn.net/?f=%5Cint%20%5C%3A%5C%3A3%5Ccdot%20%5Cfrac%7Bx%7D%7B%5Cleft%28x-1%5Cright%29%5E2%7Ddx)
![\mathrm{Take\:the\:constant\:out}:\quad \int a\cdot f\left(x\right)dx=a\cdot \int f\left(x\right)dx](https://tex.z-dn.net/?f=%5Cmathrm%7BTake%5C%3Athe%5C%3Aconstant%5C%3Aout%7D%3A%5Cquad%20%5Cint%20a%5Ccdot%20f%5Cleft%28x%5Cright%29dx%3Da%5Ccdot%20%5Cint%20f%5Cleft%28x%5Cright%29dx)
![=3\cdot \int \frac{x}{\left(x-1\right)^2}dx](https://tex.z-dn.net/?f=%3D3%5Ccdot%20%5Cint%20%5Cfrac%7Bx%7D%7B%5Cleft%28x-1%5Cright%29%5E2%7Ddx)
![\mathrm{Apply\:u-substitution:}\:u=x-1](https://tex.z-dn.net/?f=%5Cmathrm%7BApply%5C%3Au-substitution%3A%7D%5C%3Au%3Dx-1)
![=3\cdot \int \frac{u+1}{u^2}du](https://tex.z-dn.net/?f=%3D3%5Ccdot%20%5Cint%20%5Cfrac%7Bu%2B1%7D%7Bu%5E2%7Ddu)
![\mathrm{Expand}\:\frac{u+1}{u^2}:\quad \frac{1}{u}+\frac{1}{u^2}](https://tex.z-dn.net/?f=%5Cmathrm%7BExpand%7D%5C%3A%5Cfrac%7Bu%2B1%7D%7Bu%5E2%7D%3A%5Cquad%20%5Cfrac%7B1%7D%7Bu%7D%2B%5Cfrac%7B1%7D%7Bu%5E2%7D)
![=3\cdot \int \frac{1}{u}+\frac{1}{u^2}du](https://tex.z-dn.net/?f=%3D3%5Ccdot%20%5Cint%20%5Cfrac%7B1%7D%7Bu%7D%2B%5Cfrac%7B1%7D%7Bu%5E2%7Ddu)
![\mathrm{Apply\:the\:Sum\:Rule}:\quad \int f\left(x\right)\pm g\left(x\right)dx=\int f\left(x\right)dx\pm \int g\left(x\right)dx](https://tex.z-dn.net/?f=%5Cmathrm%7BApply%5C%3Athe%5C%3ASum%5C%3ARule%7D%3A%5Cquad%20%5Cint%20f%5Cleft%28x%5Cright%29%5Cpm%20g%5Cleft%28x%5Cright%29dx%3D%5Cint%20f%5Cleft%28x%5Cright%29dx%5Cpm%20%5Cint%20g%5Cleft%28x%5Cright%29dx)
![=3\left(\int \frac{1}{u}du+\int \frac{1}{u^2}du\right)](https://tex.z-dn.net/?f=%3D3%5Cleft%28%5Cint%20%5Cfrac%7B1%7D%7Bu%7Ddu%2B%5Cint%20%5Cfrac%7B1%7D%7Bu%5E2%7Ddu%5Cright%29)
as
∵ ![\mathrm{Use\:the\:common\:integral}:\quad \int \frac{1}{u}du=\ln \left(\left|u\right|\right)](https://tex.z-dn.net/?f=%5Cmathrm%7BUse%5C%3Athe%5C%3Acommon%5C%3Aintegral%7D%3A%5Cquad%20%5Cint%20%5Cfrac%7B1%7D%7Bu%7Ddu%3D%5Cln%20%5Cleft%28%5Cleft%7Cu%5Cright%7C%5Cright%29)
∵ ![\mathrm{Apply\:the\:Power\:Rule}:\quad \int x^adx=\frac{x^{a+1}}{a+1},\:\quad \:a\ne -1](https://tex.z-dn.net/?f=%5Cmathrm%7BApply%5C%3Athe%5C%3APower%5C%3ARule%7D%3A%5Cquad%20%5Cint%20x%5Eadx%3D%5Cfrac%7Bx%5E%7Ba%2B1%7D%7D%7Ba%2B1%7D%2C%5C%3A%5Cquad%20%5C%3Aa%5Cne%20-1)
so
![=3\left(\ln \left|u\right|-\frac{1}{u}\right)](https://tex.z-dn.net/?f=%3D3%5Cleft%28%5Cln%20%5Cleft%7Cu%5Cright%7C-%5Cfrac%7B1%7D%7Bu%7D%5Cright%29)
![\mathrm{Substitute\:back}\:u=x-1](https://tex.z-dn.net/?f=%5Cmathrm%7BSubstitute%5C%3Aback%7D%5C%3Au%3Dx-1)
![=3\left(\ln \left|x-1\right|-\frac{1}{x-1}\right)](https://tex.z-dn.net/?f=%3D3%5Cleft%28%5Cln%20%5Cleft%7Cx-1%5Cright%7C-%5Cfrac%7B1%7D%7Bx-1%7D%5Cright%29)
![\mathrm{Add\:a\:constant\:to\:the\:solution}](https://tex.z-dn.net/?f=%5Cmathrm%7BAdd%5C%3Aa%5C%3Aconstant%5C%3Ato%5C%3Athe%5C%3Asolution%7D)
![=3\left(\ln \left|x-1\right|-\frac{1}{x-1}\right)+C](https://tex.z-dn.net/?f=%3D3%5Cleft%28%5Cln%20%5Cleft%7Cx-1%5Cright%7C-%5Cfrac%7B1%7D%7Bx-1%7D%5Cright%29%2BC)
Therefore,
![\int \:3\cdot \frac{x}{\left(x-1\right)^2}dx=3\left(\ln \left|x-1\right|-\frac{1}{x-1}\right)+C](https://tex.z-dn.net/?f=%5Cint%20%5C%3A3%5Ccdot%20%5Cfrac%7Bx%7D%7B%5Cleft%28x-1%5Cright%29%5E2%7Ddx%3D3%5Cleft%28%5Cln%20%5Cleft%7Cx-1%5Cright%7C-%5Cfrac%7B1%7D%7Bx-1%7D%5Cright%29%2BC)
So I did 5/2 and I got 2.5
5 divided by 2 = 2.5
Not 100% sure if I'm right though
Step-by-step explanation:
<h2>13. </h2>
![\implies\sf{ {x}^{2} = 144 } \\ \\ \implies\sf{ x = \pm \sqrt{144} } \\ \\ \implies\sf{ x = \pm 12 }](https://tex.z-dn.net/?f=%20%20%5Cimplies%5Csf%7B%20%7Bx%7D%5E%7B2%7D%20%3D%20144%20%7D%20%5C%5C%20%20%5C%5C%20%20%5Cimplies%5Csf%7B%20x%20%3D%20%20%5Cpm%20%5Csqrt%7B144%7D%20%7D%20%20%20%5C%5C%20%20%5C%5C%20%5Cimplies%5Csf%7B%20x%20%3D%20%20%5Cpm%2012%20%7D%20%20)
<h2>14.</h2>
![\implies\sf{ {x}^{2} = \dfrac{25}{289} } \\ \\ \implies\sf{ x = \pm \sqrt{ \frac{25}{289} } } \\ \\ \implies\sf{ x = \pm \frac{5}{17} }](https://tex.z-dn.net/?f=%20%20%5Cimplies%5Csf%7B%20%7Bx%7D%5E%7B2%7D%20%3D%20%20%5Cdfrac%7B25%7D%7B289%7D%20%20%7D%20%5C%5C%20%20%5C%5C%20%20%5Cimplies%5Csf%7B%20x%20%3D%20%20%5Cpm%20%5Csqrt%7B%20%5Cfrac%7B25%7D%7B289%7D%20%7D%20%7D%20%20%20%5C%5C%20%20%5C%5C%20%5Cimplies%5Csf%7B%20x%20%3D%20%20%5Cpm%20%20%5Cfrac%7B5%7D%7B17%7D%20%20%7D%20%20)
<h2>15.</h2>
![\implies\sf{ {x}^{3} = 216 } \\ \\ \implies\sf{ x = \sqrt[3]{216} } \\ \\ \implies\sf{ x = 6 }](https://tex.z-dn.net/?f=%20%20%5Cimplies%5Csf%7B%20%7Bx%7D%5E%7B3%7D%20%3D%20216%20%7D%20%5C%5C%20%20%5C%5C%20%20%5Cimplies%5Csf%7B%20x%20%3D%20%20%20%5Csqrt%5B3%5D%7B216%7D%20%20%7D%20%20%20%5C%5C%20%20%5C%5C%20%5Cimplies%5Csf%7B%20x%20%3D%20%206%20%7D%20%20)