giúp mình với mai mình học rồi

Question

bai 1. 11/3.40/13+37/5:7/33-(11/13.1/3+33/7:5/2)

bai 2.tim x

a,3.(x-1)-5.(-7)=(-2)^3-2x

b,2./(1-x)^2+1/-2^2.3=8

bai 3,cho bieu thuc 

M=n+1/n+1 - 3-8n/n+1 + 8/n+1

tim cac gia tri cua n de bieu thuc M co gia tri nguyen

bai 4,So hoc sinh cua 1 truong ko qua 1000 em,neuxeptoan bo so hoc sinh cua truong do thanh cac hang,moi hang 20 nguoi thi con thieu 5 nguoi,neu xep moi hang 25 nguoi hoac 30 nguoi thi deu thua 15 nguoi , neu xep 42 hang thi vua du . hoi truong do co bao nhieu hoc sinh 

bai 5,cho bieu thuc 

A=2+2^2+...+2^200

c/m rang 

a, A+2 la 1 luy thua cua 2

b, Achia het cho 30

c,A co phai la so chinh phuong ko ? vi sao ?

bai 6,cho 2 bieu thuc 

A=1/1+2 + 1/1+2+3 + ...1/1+2+3+...+99

B=1 + 1/2^2+1/3^2 + ...+1/29^2

c/m rang A