15.6+5.2+6.5+d=15.6

Solution for 15.6+5.2+6.5+d=15.6 equation:

Simplifying
15.6 + 5.2 + 6.5 + d = 15.6

Combine like terms: 15.6 + 5.2 = 20.8
20.8 + 6.5 + d = 15.6

Combine like terms: 20.8 + 6.5 = 27.3
27.3 + d = 15.6

Solving
27.3 + d = 15.6

Solving for variable 'd'.

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

Add '-27.3' to each side of the equation.
27.3 + -27.3 + d = 15.6 + -27.3

Combine like terms: 27.3 + -27.3 = 0.0
0.0 + d = 15.6 + -27.3
d = 15.6 + -27.3

Combine like terms: 15.6 + -27.3 = -11.7
d = -11.7

Simplifying
d = -11.7