1. Differentiate $y$ with respect to $x$ using the quotient rule.
Let u=3e2x and v=2x+1.
dxdu=6e2x
dxdv=2
dxdy=v2vdxdu−udxdv
dxdy=(2x+1)2(2x+1)(6e2x)−(3e2x)(2)
2. Simplify the numerator of the derivative.
dxdy=(2x+1)212xe2x+6e2x−6e2x
dxdy=(2x+1)212xe2x
3. Express the derivative in the given form to find $k$.
We are given dxdy=2x+1kxy.
Substitute y=2x+13e2x into this expression:
dxdy=2x+1kx(2x+13e2x)=(2x+1)23kxe2x
Equating the two expressions for dxdy:
(2x+1)212xe2x=(2x+1)23kxe2x
Comparing the coefficients of xe2x:
12=3k
k=4