-0.4(a-15)=0.1(a-15)

Solution for -0.4(a-15)=0.1(a-15) equation:

Simplifying
-0.4(a + -15) = 0.1(a + -15)

Reorder the terms:
-0.4(-15 + a) = 0.1(a + -15)
(-15 * -0.4 + a * -0.4) = 0.1(a + -15)
(6 + -0.4a) = 0.1(a + -15)

Reorder the terms:
6 + -0.4a = 0.1(-15 + a)
6 + -0.4a = (-15 * 0.1 + a * 0.1)
6 + -0.4a = (-1.5 + 0.1a)

Solving
6 + -0.4a = -1.5 + 0.1a

Solving for variable 'a'.

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

Add '-0.1a' to each side of the equation.
6 + -0.4a + -0.1a = -1.5 + 0.1a + -0.1a

Combine like terms: -0.4a + -0.1a = -0.5a
6 + -0.5a = -1.5 + 0.1a + -0.1a

Combine like terms: 0.1a + -0.1a = 0.0
6 + -0.5a = -1.5 + 0.0
6 + -0.5a = -1.5

Add '-6' to each side of the equation.
6 + -6 + -0.5a = -1.5 + -6

Combine like terms: 6 + -6 = 0
0 + -0.5a = -1.5 + -6
-0.5a = -1.5 + -6

Combine like terms: -1.5 + -6 = -7.5
-0.5a = -7.5

Divide each side by '-0.5'.
a = 15

Simplifying
a = 15