25: \(\left(-25\right)+8-3\)
\(=\left(-25\right)+\left(8-3\right)\)
=-25+5
=-20
26: \(\left(-28\right)+2+6\)
\(=\left(-28\right)+\left(2+6\right)\)
=-28+8
=-20
27: \(\left(-1\right)+9+12\)
\(=\left(-1+12\right)+9\)
=11+9
=20
28: \(33+8-40\)
\(=\left(33+8\right)-40\)
=41-40
=1
29: \(\left(-80\right)+20+60\)
\(=\left(-80\right)+\left(20+60\right)\)
=-80+80
=0
30: \(\left(-12\right)+3+9\)
\(=\left(-12\right)+\left(3+9\right)\)
=-12+12
=0
25) (-25) + 8 - 3
= (-25 - 3) + 8
= -28 + 8
= -20
26) (-28) + 2 + 6
= -28 + 8
= -20
27) (-1) + 9 + 12
= -1 + (9 + 12)
= -1 + 21
= 20
28) 33 + 8 - 40
= (33 + 8) - 40
= 41 - 40
= 1
29) (-80) + 20 + 60
= -80 + (20 + 60)
= -80 + 80
= 0
30) (-12) + 3 + 9
= -12 + (3 + 9)
= -12 + 12
= 0