(7r+s+4)(-.4)=

Solution for (7r+s+4)(-.4)= equation:

Simplifying
(7r + s + 4)(-0.4) = 0

Reorder the terms:
(4 + 7r + s)(-0.4) = 0

Reorder the terms for easier multiplication:
-0.4(4 + 7r + s) = 0
(4 * -0.4 + 7r * -0.4 + s * -0.4) = 0
(-1.6 + -2.8r + -0.4s) = 0

Solving
-1.6 + -2.8r + -0.4s = 0

Solving for variable 'r'.

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

Add '1.6' to each side of the equation.
-1.6 + -2.8r + 1.6 + -0.4s = 0 + 1.6

Reorder the terms:
-1.6 + 1.6 + -2.8r + -0.4s = 0 + 1.6

Combine like terms: -1.6 + 1.6 = 0.0
0.0 + -2.8r + -0.4s = 0 + 1.6
-2.8r + -0.4s = 0 + 1.6

Combine like terms: 0 + 1.6 = 1.6
-2.8r + -0.4s = 1.6

Add '0.4s' to each side of the equation.
-2.8r + -0.4s + 0.4s = 1.6 + 0.4s

Combine like terms: -0.4s + 0.4s = 0.0
-2.8r + 0.0 = 1.6 + 0.4s
-2.8r = 1.6 + 0.4s

Divide each side by '-2.8'.
r = -0.5714285714 + -0.1428571429s

Simplifying
r = -0.5714285714 + -0.1428571429s