800=A*(1-.42)

Solution for 800=A*(1-.42) equation:

Simplifying
800 = A(1 + -0.42)

Combine like terms: 1 + -0.42 = 0.58
800 = A(0.58)

Reorder the terms for easier multiplication:
800 = 0.58A

Solving
800 = 0.58A

Solving for variable 'A'.

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

Add '-0.58A' to each side of the equation.
800 + -0.58A = 0.58A + -0.58A

Combine like terms: 0.58A + -0.58A = 0.00
800 + -0.58A = 0.00

Add '-800' to each side of the equation.
800 + -800 + -0.58A = 0.00 + -800

Combine like terms: 800 + -800 = 0
0 + -0.58A = 0.00 + -800
-0.58A = 0.00 + -800

Combine like terms: 0.00 + -800 = -800
-0.58A = -800

Divide each side by '-0.58'.
A = 1379.310345

Simplifying
A = 1379.310345