5.6=a*(2-5.25)2-6.9

Solution for 5.6=a*(2-5.25)2-6.9 equation:

Simplifying
5.6 = a(2 + -5.25) * 2 + -6.9

Combine like terms: 2 + -5.25 = -3.25
5.6 = a(-3.25) * 2 + -6.9

Reorder the terms for easier multiplication:
5.6 = -3.25 * 2a + -6.9

Multiply -3.25 * 2
5.6 = -6.5a + -6.9

Reorder the terms:
5.6 = -6.9 + -6.5a

Solving
5.6 = -6.9 + -6.5a

Solving for variable 'a'.

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

Add '6.5a' to each side of the equation.
5.6 + 6.5a = -6.9 + -6.5a + 6.5a

Combine like terms: -6.5a + 6.5a = 0.0
5.6 + 6.5a = -6.9 + 0.0
5.6 + 6.5a = -6.9

Add '-5.6' to each side of the equation.
5.6 + -5.6 + 6.5a = -6.9 + -5.6

Combine like terms: 5.6 + -5.6 = 0.0
0.0 + 6.5a = -6.9 + -5.6
6.5a = -6.9 + -5.6

Combine like terms: -6.9 + -5.6 = -12.5
6.5a = -12.5

Divide each side by '6.5'.
a = -1.923076923

Simplifying
a = -1.923076923