8（a+2)的2次方+3| b-3 |+16(c+0.5)的2次方=0.

8（a+2)^2=0.
a=-2

3| b-3 |=0
b=3
16(c+0.5)^2=0.
c=-0.5
（a^b+2c)^2
=[(-2)^3+2*(-0.5)]^2
=(-8-1)^2
=(-9)^2
=81