-21a+-28a-6=10.2

Solution for -21a+-28a-6=10.2 equation:

Simplifying
-21a + -28a + -6 = 10.2

Reorder the terms:
-6 + -21a + -28a = 10.2

Combine like terms: -21a + -28a = -49a
-6 + -49a = 10.2

Solving
-6 + -49a = 10.2

Solving for variable 'a'.

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

Add '6' to each side of the equation.
-6 + 6 + -49a = 10.2 + 6

Combine like terms: -6 + 6 = 0
0 + -49a = 10.2 + 6
-49a = 10.2 + 6

Combine like terms: 10.2 + 6 = 16.2
-49a = 16.2

Divide each side by '-49'.
a = -0.3306122449

Simplifying
a = -0.3306122449