用地等式计算(运用公式)1.1+3+9+27+81+2432.1+2+4+8+16+32+643.1+2+4+5+7+8
2个回答

1:原式=[1*(1-3^6)]/(1-3)

=(1-729)/-2

=-728/-2

=364

2:原式=[1*(1-2^7)]/(1-2)

=(1-128)/-1

=127

3:原式=3+9+15+21+27+33

=(3+33)*6/2

=36*3

=108

4:原式=1+5.3*7+0.4+0.6+1+1.2+1.6+1.8

=1+37.1+1+1+3+1.6

=38.1+6.6

=44.7

5:原式=100+200+300+400+500+600+22*6

=(100+600)*6/2+132

=700*3+132

=2100+132

=2232

6:原式=100+200+300+400+500+600+33*6

=(100+600)*6/2+198

=700*3+198

=2100+198

=2298