帮我找初一的脱式题或简算题,越多越好

99...9×(1000...-1)+1000..+99..9
=99...9×(1000...-1+1)+1000..
=1000...×(99...9+1)
=1000...^2
-ab（a的平方b的5次方+a（b的3次方）-2b）
=-a^3b^6-a^2b^4+2ab^2
=-(ab^2)^3-(ab^2)^2+2ab^2
=-(-2)^3-(-2)^2+2*(-2)
=8-4-4
=0
(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+(1/6-1/7)+(1/7-1/8)=1/2-1/8=3/8=0.375
1/8+1/8*1/3+1/8*1/6+1/8*1/10+1/8*1/15
=1/8*(1+1/3+1/6+1/10+1/15)
=1/8*5/3
=5/24
1/8(1/4(1/2(x+1)+3)+7)=1
1/4(1/2(x+1)+3)+7=8
1/4(1/2(x+1)+3)=1
1/2(x+1)+3=4
1/2(x+1)=1
x+1=2
x=1
脱式题
2700×（506－499）÷900
=2700×7÷900
=18900÷900
=21 =10
33.02－（148.4－90.85）÷2.5
=33.02－57.55÷2.5
=33.02－23.02
=10
1÷1－1）÷5.1 ④18.1＋（3－0.299÷0.23）×1
=（1－1）÷5.1 =18.1＋1.7X1
=0÷5.1 =18.1＋1.7
=0 =19.8
没时间了 就这么多