M = 30 + 31 + 32 + 33 + ... + 3200
3M = 3 + 32 + 33 + 34 + ... + 3201
3M - M = ( 3 + 32 + 33 + 34 + ... + 3201 ) - ( 30 + 31 + 32 + 33 + ... + 3200 )
2M = 3201 - 30
M = ( 3201 - 30 ) : 2
tinh tong
A = 1+2+3+.......+200
B =2+4+6+........+80
C= 1+3+5+.........+81
tinh tong phan so A=1/3+1/3^2+1/3^3+...+1/3^100
Biet 1^2+2^2+3^2+..+10^2=385
Hay tinh tong cua S=100^+200^2+300^2+..+1000^2
lam co loi giai nhe
Tinh tong M =(-1)+2+(-3)+4+(-5)+…+(-4025)+4026
thuc hien tinh :E=1+1/2(1+2)+1/3(1+2+3)+1/4(1+2+3+4)+.......+1/200(1+2+3+.....+200)
Tinh cac tong sau
\(H=\frac{1}{7}+\frac{1}{7^2}+\frac{1}{7^3}+...+\frac{1}{7^{100}}\)
\(I=\frac{4}{5}+\frac{4}{5^2}+\frac{4}{5^3}+...+\frac{4}{5^{200}}\)
tinh B=1+1/2(1+2)+1/3(1+2+3)+1/4+(1+2+3+4)+...+1/200(1+2+....+200)
bai1:tinh tong S=1.3+3.5+5.7+...+99.101
bai2 :tinh tong S=1.4+4.7+7.10+...+2017.2020
bai 3: tinh tong N=2.4+4.6+6.8+..+100.102
bai 4: tinh tóng=2.6+6.10+10.14+14.18+...+42.46+50.54
bai 5:tinh tongB=2^2+4^2+6^2+...+100^2
bai 6:C=1^2+3^2+...+100^2
bai7: biet 1^2+2^2+3^2+...+10^2=385 tinh tong 2^2+4^2+6^2+...+20^2
bai 8: tinh tong s=1^2+2^2+3^2+...+99^2
tinh tong S= 3/2 +3/2^2 +3/2^3+......+3/2^9
