1.99*9.9+0.099
=1.99*9.9+9.9*0.01
=9.9*(1.99+0.01)
=9.9*2
=19.8
1.99 ×9.9+0.099=2 ×9.9-0.01 ×9.9+0.099=19.8-0.099+0.099=19.8
你好!根据题意列算式为
1.9-1.9×(1.9×1.9)
=1.9×(1-1.9×1.9
=1.9×(-2.61)
=-4.959
希望可以帮到你请采纳谢谢!
九点九乘四点五加零点九九乘56减零点九九
=0.99×45+0.99×56-0.99×1
=0.99×(45+56-1)
=0.99×100
=99
是20.09吗?如果是
20.09*37-200.9*1.9-2009*0.82
=2009*0.37-2009*0.19-2009*0.82=2009x(0.37-0.19-0.82)=2009x(-0.64)=-1285.76
20.9×37-200.09×1.9-2009×0.82
= 20.9×37 - 20.009×19 - 20.09×82
= 20×(37-19-82) + (0.9×37-0.009×19-0.09×82)
= -20×64 + 0.09×(370-1.9-82)
= -1280 + 25.749
= -1254.251
1÷8×9.9+1.9×0.125-0.125 化小数为分数就能提取八分之一 ,即0.125=1/8
=1/8×9.9+1.9×1/8-1/8
=1/8×(9.9+1.9)-1/8
=1/8×11.8-1/8 11.8=11又4/5
=1/8×(11又4/5)-1/8
=59/40-1/8
=27/20
=1.35
99.99×0.8+11.11×2.8
=11.11×7.2+11.11×2.8
=11.11×(7.2+2.8)
=11.11×10
=111.1
99.99x0.8+11.11x1.8=99.99x0.8+11.11x(1+0.8)=99.99x0.8+11.11+11.11x0.8=0.8x(99.99+11.11)+11.11=0.8x111.1+11.11=99.99
3.9-3.9*0.99=3.9(1-0.99)=3.9*0.01=0.039