1, tim x bết:

,\(\frac{\left(-5^4\right).\left(-15^2\right)-5^4.\left(-3^2.5\right)}{\left(-3^4\right).25^2-\left(-15^2\right).225.5}\)\(:\)\(\frac{x}{5}\)\(=\frac{-1}{6}\)

2, cho A=\(\frac{20}{30}+\frac{20}{70}+\frac{20}{126}+...+\frac{20}{798}\)

B=\(\left(\frac{41}{2}.\frac{42}{2}.\frac{43}{2}...\frac{80}{2}\right):\left(1.3.5...79\right)\)

So sánh A và B.

3, Tính nhanh.

\(\frac{0,875+\frac{1}{2}-7\%-\frac{1}{58}}{\frac{1}{25}-\frac{1}{2}-\frac{2}{7}+\frac{2}{203}}\)\(-125\%\)

HELP  ME  PLEASE......

Tính hợp lý (nếu được)

\(a\) \(19\frac{5}{8}\)\(:\)\(1\frac{5}{7}\)\(-\) \(15\frac{5}{8}\) \(:\) \(\frac{12}{17}\)\(-\)\(1\frac{1}{3}\)

\(b\) \(\frac{2}{5}\)\(.\)\(\frac{1}{3}\)\(-\) \(\frac{2}{15}\)\(:\) \(\frac{1}{5}\)\(+\) \(\frac{3}{5}\)\(.\) \(\frac{1}{3}\)

\(c\)\(\left(3\frac{1}{3}+2,5\right):\left(3\frac{1}{6}-4\frac{1}{5}\right)-\frac{11}{31}\)

\(f\)\(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)

\(g\)\(\left(\frac{2}{5}\right)^2+5\frac{1}{2}.\left(4,5-2\right)+\frac{2^3}{\left(-4\right)}\)

\(h\)\(\frac{4}{9}.19\frac{1}{3}-\frac{4}{9}.39\frac{1}{3}\)

\(k\)\(125\%.\left(\frac{-1}{2}\right)^2:\left(1\frac{5}{16}-1,5\right)+2008^0\)

\(m\)\(F=\frac{1}{18}+\frac{1}{54}+\frac{1}{108}+...+\frac{1}{990}\)

Làm bao nhiêu cũng được nha, càng nhiều càng tốt

1.tìm x

a) 7\(^{\left(x-2\right).\left(2x+3\right)}\)= 1

b)9\(^{x+1}\)- 5 . 3\(^{2x}\)= 324

c) /x-1/ - \(\frac{1}{4}\)= \(\frac{5}{2}\)

2.Tính

(1 - \(\frac{1}{4}\))(1-\(\frac{1}{9}\))(1-\(\frac{1}{16}\))....( 1 - \(\frac{1}{81}\))(1-\(\frac{1}{100}\))

Tính gtri biểu thức:

P =\(\frac{5}{2.1}\)+\(\frac{4}{1.11}\)+\(\frac{3}{11.2}\)+\(\frac{1}{2.15}\)+\(\frac{13}{15.4}\)

Q =\(\left(1-\frac{1}{2}\right)\).\(\left(1-\frac{1}{3}\right)\).\(\left(1-\frac{1}{4}\right)\).... \(\left(1-\frac{1}{20}\right)\)

Giúp mị nha mina-san! :))

THỰC HIỆN PHÉP TÍNH:

a,\(\frac{2}{5}\)+\(\frac{-1}{6}\)-\(\frac{3}{4}\)-\(-\frac{2}{3}\)

b,\(\frac{7}{10}\)-\(\frac{-3}{4}\)+\(-\frac{5}{6}\)-\(\frac{1}{5}\)+\(-\frac{2}{3}\)

c,\(\left(\frac{1}{2}-0,75\right)\times\left(0,2-\frac{2}{5}\right)\)/ \(\frac{5}{9}-1\frac{1}{12}\)

d,\(\frac{2}{3}+\frac{2}{7}-\frac{1}{14}\)/ \(-1-\frac{3}{7}+\frac{3}{28}\)

giải ra cách làm nha ai xong tui tích 

Thực hiện phép tính:

a) (\(\frac{3}{8}\)+ \(\frac{-3}{4}\)+ \(\frac{7}{12}\)) : \(\frac{5}{6}\)+ \(\frac{1}{2}\)

b) \(\frac{1}{2}\)+ \(\frac{3}{4}\)- (\(\frac{3}{4}\)- \(\frac{4}{5}\))

c) \(6\frac{5}{12}\): \(2\frac{3}{4}\)+ \(11\frac{1}{4}\). (\(\frac{1}{3}\)- \(\frac{1}{5}\))

d) (\(\frac{7}{8}\)- \(\frac{3}{4}\)) . \(1\frac{1}{3}\)- \(\frac{2}{7}\). (3,5)²

e) (\(\frac{3}{5}\)+ 0,415 - \(\frac{3}{200}\)) .\(2\frac{2}{3}\). 0,25

f) \(\frac{5}{16}\): 0,125 - (\(2\frac{1}{4}\)- 0,6) . \(\frac{10}{11}\)

g) 0,25 : (10,3 - 9,8) - \(\frac{3}{4}\)

h) \(1\frac{13}{15}\). 0,75 - (\(\frac{11}{20}\)+ 25%) : \(\frac{7}{3}\)

i) \(\frac{\left(\frac{1}{2}-0,75\right).\left(0,2-\frac{2}{5}\right)}{\frac{5}{9}-1\frac{1}{12}}\)

k) \(\frac{\frac{2}{3}+\frac{2}{7}-\frac{1}{14}}{-1-\frac{3}{7}+\frac{3}{28}}\)

bài 1 thực hiện phép tính, tính nhanh nếu có thể

a, \(\frac{-11}{23}.\frac{6}{7}+\frac{8}{7}.\frac{-11}{23}-\frac{1}{23}\)

b,\(0,75.1\frac{7}{9}-1\frac{2}{5}:\frac{-21}{20}\)

c,\(2.\frac{3}{7}+\left(\frac{2}{9}-1\frac{3}{7}\right)-\frac{5}{3}:\frac{1}{9}\)

d,\(11\frac{1}{4}-\left(2\frac{5}{7}+5\frac{1}{4}\right)\)

e,\(\left(6-2\frac{4}{5}\right).3\frac{1}{8}-1\frac{3}{5}:25\%\)

g,\(0,2.\frac{15}{36}-\left(\frac{2}{5}+\frac{2}{3}\right):1\frac{1}{5}\)

h,\(2\frac{1}{3}-\frac{1}{3}.\left(\frac{-3}{2}+\left(\frac{2}{3}+0,4.5\right)\right)\)

i,\(\frac{1}{3}.\frac{5}{7}-\frac{7}{27}.\frac{36}{14}\)

k,\(\left(\frac{-5}{28}+1,75+\frac{8}{35}\right):\left(-3\frac{9}{20}\right)\)

l,\(\left(20+9\frac{1}{4}\right):2\frac{1}{4}\)

m,\(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{12.13}\)

n,\(\frac{5}{1.3}+\frac{5}{3.5}+\frac{5}{5.7}+...+\frac{5}{99.101}\)

1.Viết dưới dạng thu gọn 
a, \(8^5.64^2.16^3\)
b, \(81^7.243^3.3^{11}.9^7\)
c. \(6^{15}.8^{17}.9^{31}.81^31024^5\)
2. tìm x biết
a, \(\frac{4}{15}:x+\frac{-1}{3}=\frac{5}{9}\)
b,\(\left(3,25-\frac{2}{3}x\right):\frac{-7}{4}=-3\)
c, \(71+\left(26-3x\right):5=75\)
d, \(3+2^{x-1}=24-[4^2-\left(2^2-1\right)]\)
e, \(\frac{5}{7}-\left|3x+1\right|=\frac{-2}{7}\)
3.tính
a, \(\left(\frac{2}{3}\right)^2:\left(-8\right)-\left(\frac{-1}{4}+\frac{9}{20}\right):1\frac{4}{5}\)
b,\(0,8.\frac{-15}{14}-\frac{4}{5}-\frac{13}{14}-1\frac{2}{5}\)
CÁC BẠN GIÚP MÌNH VỚI MÌNH ĐANG CẦN GẤP
THANKS