r(x)=6ln(1.8)(1.8x)

Solution for r(x)=6ln(1.8)(1.8x) equation:

Simplifying
r(x) = 6ln(1.8)(1.8x)

Multiply r * x
rx = 6ln(1.8)(1.8x)

Remove parenthesis around (1.8x)
rx = 6ln * 1.8 * 1.8x

Reorder the terms for easier multiplication:
rx = 6 * 1.8 * 1.8ln * x

Multiply 6 * 1.8
rx = 10.8 * 1.8ln * x

Multiply 10.8 * 1.8
rx = 19.44ln * x

Multiply ln * x
rx = 19.44lnx

Solving
rx = 19.44lnx

Solving for variable 'r'.

Move all terms containing r to the left, all other terms to the right.

Divide each side by 'x'.
r = 19.44ln

Simplifying
r = 19.44ln