1,解原式=-28-[-(13.25+14.75)+18]
=-28+10
=-18
2,6.5x-2x-2=14
4.5x=16
x=32/9
3,x-(11/6)=1
x=17/6
4,2*(x^2-x-5+2x^2-x+3)
=2*(3x^2-2x-2)
=6x^2-4x-4
5,3m^2-5m-4+2m+m^2
=4m^2-3m-4
把m=-1/2代人4m^2-3m-4=1-(-3/2)-4=-3/2
所以所求代数式的值是-3/2