So sanh

\(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{90}+\frac{1}{100}.\)va 100

cac ban giai chi tiet giup mk voi

Bai 1 : Thuc hien cac phep tinh ( tinh nhanh neu co the ) :

a) \(2\frac{1}{3}-\frac{1}{3}\)\(:\)\(\left[15\%+\left(-\frac{2}{3}+0,4.5\right)\right]\)

GIUP MK VOI NHA 

     MK DAG CAN GAP 

            AI LAM NHANH VA DUNG THI MK SE TICK CHO NHA  ^ _ <

Chứng minh rằng: \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{100^2}< 1\)1

ai nhanh nhất mk tk nha ,kb vs mk 

bai 1 :thuc hien phep tinh

a)\(\frac{-5}{2}:\left(\frac{3}{4}-\frac{1}{2}\right)\)      b)  \(11\frac{3}{13}-\left(2\frac{4}{7}+5\frac{3}{13}\right)\)     c)\(\left(\frac{-5}{24}+0,75+\frac{7}{12}\right):\left(-2\frac{1}{4}\right)^2\)

AI LAM NHANH VA DUNG THI MK SE TICK CHO NHA

MK DAG CAN GAP !!!!!!! CAC BAN LAM NHANH LEN NHA

Cau 1 : Tinh hop ly

a) (326-43) + (174-57)

b) (351-875) - (125-149)

c) -418-{-218-[-118-(-318)+2012)]}

d) (-2)+7+(-12)+17+...+(-52)+57

e) (-30)+(-29)+...+49+50

Mk se tick cho ai tra loi cho mk dau tien nko ghi cach lm nx nhe thank you cac bn

tim x la so nguyen

 1. \(\frac{12}{x}=\frac{x}{3}\)

2. \(\frac{x}{2}+\frac{x}{3}=\frac{1}{4}\)

giai giup mk nha cac bn 

tinh hop li :

                 \(\frac{\left(\frac{1}{5}-\frac{2}{7}\right)\cdot\frac{3}{4}-\frac{3}{4}\cdot\left(\frac{1}{3}-\frac{2}{7}\right)}{\frac{1}{5}\cdot\frac{2}{7}-\frac{1}{3}\cdot\left(\frac{2}{7}+\frac{3}{9}\right)+\frac{3}{9}+\frac{1}{5}}\)

cham la nhan nha cac ban 

ai nhanh mk tick cho

Tinh cac tong sau

\(H=\frac{1}{7}+\frac{1}{7^2}+\frac{1}{7^3}+...+\frac{1}{7^{100}}\)

\(I=\frac{4}{5}+\frac{4}{5^2}+\frac{4}{5^3}+...+\frac{4}{5^{200}}\)

Cho 

\(A=\frac{1}{^{1^2}}+\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+....+\frac{1}{50^2}\) 

Chứng minh A < 2

Nhanh giúp mk nha , ai nhanh nhất chính xác nhất mk sẽ tick