(x*7)-(500+X)=400

Solution for (x*7)-(500+X)=400 equation:

Simplifying
(x * 7) + -1(500 + X) = 400

Reorder the terms for easier multiplication:
(7x) + -1(500 + X) = 400
(7x) + (500 * -1 + X * -1) = 400
(7x) + (-500 + -1X) = 400

Reorder the terms:
-500 + -1X + (7x) = 400

Solving
-500 + -1X + (7x) = 400

Solving for variable 'X'.

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

Add '500' to each side of the equation.
-500 + -1X + 500 + (7x) = 400 + 500

Reorder the terms:
-500 + 500 + -1X + (7x) = 400 + 500

Combine like terms: -500 + 500 = 0
0 + -1X + (7x) = 400 + 500
-1X + (7x) = 400 + 500

Combine like terms: 400 + 500 = 900
-1X + (7x) = 900

Add '(-7x)' to each side of the equation.
-1X + (7x) + (-7x) = 900 + (-7x)

Combine like terms: (7x) + (-7x) = 0
-1X + 0 = 900 + (-7x)
-1X = 900 + (-7x)

Divide each side by '-1'.
X = -900 + (7x)

Simplifying
X = -900 + (7x)