152x98=152x100-2x152=15200-304=14896

42x98 +2x42=42*(98+2)=42*100=4200

2x68+68x98=68x(2+98)=68x100=6800

75x(100一2)=75x100+75x2=7500+150=7650

=150x(63+36+1)=150x100=15000

123x98+2x123=123*(98+2)=123*100=12300

78x160=78x100+78x60=7800+4680=12480.78x160=80x160-2x160=12800-320=12480

原式=(100-1)*98=100*98-1*98=9800-98=9702~一刻永远523为你解答,祝你学习进步~~~希望可以及时“选为满意答案”,你的采纳是我前进的动力~~~

原式=(0.8-0.02)(100-2) =(0.8-0.02)x100-(0.8-0.02)x2 =80-2-1.6+0.04 =76.44应该能看明白吧

160x99=160x100-99=16000-99=15901