400=(5000)(r)(4)

Solution for 400=(5000)(r)(4) equation:

Simplifying
400 = (5000)(r)(4)

Reorder the terms for easier multiplication:
400 = 5000 * 4r

Multiply 5000 * 4
400 = 20000r

Solving
400 = 20000r

Solving for variable 'r'.

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

Add '-20000r' to each side of the equation.
400 + -20000r = 20000r + -20000r

Combine like terms: 20000r + -20000r = 0
400 + -20000r = 0

Add '-400' to each side of the equation.
400 + -400 + -20000r = 0 + -400

Combine like terms: 400 + -400 = 0
0 + -20000r = 0 + -400
-20000r = 0 + -400

Combine like terms: 0 + -400 = -400
-20000r = -400

Divide each side by '-20000'.
r = 0.02

Simplifying
r = 0.02