400=x*y

Solution for 400=x*y equation:

Simplifying
400 = x * y

Multiply x * y
400 = xy

Solving
400 = xy

Solving for variable 'x'.

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

Add '-1xy' to each side of the equation.
400 + -1xy = xy + -1xy

Combine like terms: xy + -1xy = 0
400 + -1xy = 0

Add '-400' to each side of the equation.
400 + -400 + -1xy = 0 + -400

Combine like terms: 400 + -400 = 0
0 + -1xy = 0 + -400
-1xy = 0 + -400

Combine like terms: 0 + -400 = -400
-1xy = -400

Divide each side by '-1y'.
x = 400y-1

Simplifying
x = 400y-1