b2
11 = \(\left(28+72\right)+\left(-199+99\right)=100+100=200\)
12 = \(\left(-34+-66\right)+\left(121-21\right)=-100+100=0\)
13 = \(\left(-87-13\right)+\left(38-138\right)=-100+-100=-200\)
14 =\(\left(35+65\right)+\left(-67-33\right)=100+\left(-100\right)=0\)
15= \(35x\left(-18+-82\right)=35x\left(-100\right)=-3500\)
16= \(\left(-28\right)x\left(34+66\right)=-28x100=-2800\)
17 = \(54x\left(-121+21\right)=54x\left(-100\right)=-5400\)
18= \(35x\left(-81+-19\right)=35x\left(-100\right)=-3500\)
19= \(42x\left(-11+-66\right)=42x\left(-77\right)=-3234\)(thiếu đề ko)
20= \(51x\left(-191+91\right)=51x\left(-100\right)=-5100\)
