7(a+6)=8[a-(9-a)]

Solution for 7(a+6)=8[a-(9-a)] equation:

Simplifying
7(a + 6) = 8[a + -1(9 + -1a)]

Reorder the terms:
7(6 + a) = 8[a + -1(9 + -1a)]
(6 * 7 + a * 7) = 8[a + -1(9 + -1a)]
(42 + 7a) = 8[a + -1(9 + -1a)]
42 + 7a = 8[a + (9 * -1 + -1a * -1)]
42 + 7a = 8[a + (-9 + 1a)]

Reorder the terms:
42 + 7a = 8[-9 + a + 1a]

Combine like terms: a + 1a = 2a
42 + 7a = 8[-9 + 2a]
42 + 7a = [-9 * 8 + 2a * 8]
42 + 7a = [-72 + 16a]

Solving
42 + 7a = -72 + 16a

Solving for variable 'a'.

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

Add '-16a' to each side of the equation.
42 + 7a + -16a = -72 + 16a + -16a

Combine like terms: 7a + -16a = -9a
42 + -9a = -72 + 16a + -16a

Combine like terms: 16a + -16a = 0
42 + -9a = -72 + 0
42 + -9a = -72

Add '-42' to each side of the equation.
42 + -42 + -9a = -72 + -42

Combine like terms: 42 + -42 = 0
0 + -9a = -72 + -42
-9a = -72 + -42

Combine like terms: -72 + -42 = -114
-9a = -114

Divide each side by '-9'.
a = 12.66666667

Simplifying
a = 12.66666667