6a^2+3a^2+18-30=16

Solution for 6a^2+3a^2+18-30=16 equation:

Simplifying
6a2 + 3a2 + 18 + -30 = 16

Reorder the terms:
18 + -30 + 6a2 + 3a2 = 16

Combine like terms: 18 + -30 = -12
-12 + 6a2 + 3a2 = 16

Combine like terms: 6a2 + 3a2 = 9a2
-12 + 9a2 = 16

Solving
-12 + 9a2 = 16

Solving for variable 'a'.

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

Add '12' to each side of the equation.
-12 + 12 + 9a2 = 16 + 12

Combine like terms: -12 + 12 = 0
0 + 9a2 = 16 + 12
9a2 = 16 + 12

Combine like terms: 16 + 12 = 28
9a2 = 28

Divide each side by '9'.
a2 = 3.111111111

Simplifying
a2 = 3.111111111

Take the square root of each side:
a = {-1.763834207, 1.763834207}