Given `dy/dx +y/x=6x+2`
when the first order linear ordinary differential equation has the form of
`y'+p(x)y=q(x)`
then the general solution is ,
`y(x)=((int e^(int p(x) dx) *q(x)) dx +c)/e^(int p(x) dx)`
so,
`dy/dx +y/x=6x+2--------(1)`
`y'+p(x)y=q(x)---------(2)`
on comparing both we get,
`p(x) = 1/x and q(x)=6x+2`
so on solving with the above general solution we get:
y(x)=`((int e^(int p(x) dx) *q(x)) dx +c)/e^(int p(x) dx)`
=`((int e^(int (1/x) dx) *(6x+2)) dx +c)/e^(int 1/x dx)`
first we shall solve
`e^(int (1/x) dx)=e^ln(x) =|x|` as we know `int (1/x)dx = ln(x)`
so then we get ` e^(int (1/x) dx) =x`
since x must be greater than 0, or else`ln(x)` is undefined.
Proceeding further with
y(x) =`((int e^(int (1/x) dx) *(6x+2)) dx +c)/e^(int 1/x dx)`
=` (int x *(6x+2) dx +c)/x`
= `(int (6x^2 +2x) dx+c)/x`
=` (6x^3/3 +2x^2/2 +c)/x`
= `(2x^3+x^2+c)/x`
So, ` y= (2x^3+x^2+c)/x`
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