.3(a+1)=1.2

Solution for .3(a+1)=1.2 equation:

Simplifying
0.3(a + 1) = 1.2

Reorder the terms:
0.3(1 + a) = 1.2
(1 * 0.3 + a * 0.3) = 1.2
(0.3 + 0.3a) = 1.2

Solving
0.3 + 0.3a = 1.2

Solving for variable 'a'.

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

Add '-0.3' to each side of the equation.
0.3 + -0.3 + 0.3a = 1.2 + -0.3

Combine like terms: 0.3 + -0.3 = 0.0
0.0 + 0.3a = 1.2 + -0.3
0.3a = 1.2 + -0.3

Combine like terms: 1.2 + -0.3 = 0.9
0.3a = 0.9

Divide each side by '0.3'.
a = 3

Simplifying
a = 3