15.8=r+1.2*(Rm-5)

Solution for 15.8=r+1.2*(Rm-5) equation:

Simplifying
15.8 = r + 1.2(Rm + -5)

Reorder the terms:
15.8 = r + 1.2(-5 + mR)
15.8 = r + (-5 * 1.2 + mR * 1.2)
15.8 = r + (-6 + 1.2mR)

Reorder the terms:
15.8 = -6 + 1.2mR + r

Solving
15.8 = -6 + 1.2mR + r

Solving for variable 'm'.

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

Add '-1.2mR' to each side of the equation.
15.8 + -1.2mR = -6 + 1.2mR + -1.2mR + r

Combine like terms: 1.2mR + -1.2mR = 0.0
15.8 + -1.2mR = -6 + 0.0 + r
15.8 + -1.2mR = -6 + r

Add '-15.8' to each side of the equation.
15.8 + -15.8 + -1.2mR = -6 + -15.8 + r

Combine like terms: 15.8 + -15.8 = 0.0
0.0 + -1.2mR = -6 + -15.8 + r
-1.2mR = -6 + -15.8 + r

Combine like terms: -6 + -15.8 = -21.8
-1.2mR = -21.8 + r

Divide each side by '-1.2R'.
m = 18.16666667R-1 + -0.8333333333rR-1

Simplifying
m = 18.16666667R-1 + -0.8333333333rR-1