2(3+5)-9=a

Solution for 2(3+5)-9=a equation:

Simplifying
2(3 + 5) + -9 = a

Combine like terms: 3 + 5 = 8
2(8) + -9 = a

Multiply 2 * 8
16 + -9 = a

Combine like terms: 16 + -9 = 7
7 = a

Solving
7 = a

Solving for variable 'a'.

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

Add '-1a' to each side of the equation.
7 + -1a = a + -1a

Combine like terms: a + -1a = 0
7 + -1a = 0

Add '-7' to each side of the equation.
7 + -7 + -1a = 0 + -7

Combine like terms: 7 + -7 = 0
0 + -1a = 0 + -7
-1a = 0 + -7

Combine like terms: 0 + -7 = -7
-1a = -7

Divide each side by '-1'.
a = 7

Simplifying
a = 7