a) A=\(\left(\frac{-5}{11}\right).\frac{7}{15}.\left(\frac{11}{-5}\right).\left(-30\right)\)

b) B=\(\left(-\frac{1}{6}\right).\left(\frac{-15}{19}\right).\left(\frac{38}{45}\right)\)

c) C= \(\left(\frac{-5}{9}\right).\frac{3}{11}+\left(\frac{-13}{18}\right).\frac{3}{11}\)

d) D= \(\left(2\frac{2}{15}.\frac{9}{17}.\frac{3}{32}\right):\left(\frac{-3}{27}\right)\)

a)A=\(\frac{16^3.3^{10}+120.6^9}{4^6.3^{12}+6^{11}}\)                b)B=\(\frac{45}{19}-\left(\frac{1}{2}\left(\frac{1}{3}+\left(\frac{1}{4}\right)^{-1}\right)^-\right)^{-1}\)     c)C=\(\frac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^{10}.6^{19}-7.2^{29}.27^6}\)

d)D=\(\frac{2^{21}.3^5-4^6.81}{\left(2^2.3\right)^6+8^4.3^5}\)                e) E=\(\left(6^9.2^{10}+12^{10}\right):\left(2^{19}.27^3+15.4^9.9^4\right)\)

f) F=\(\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.24^3+45^6}\)          g)G=\(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{9}{4}\right)^3:\left(\frac{3}{16}\right)^3}{2^7.5^2+512}\)         h)H=\(x+\frac{0,2-0,375+\frac{5}{11}}{-0,3+\frac{9}{16}-\frac{15}{22}}\)với x=-1/3

1.Tìm x :

a,\(\frac{1}{5.6}+\frac{1}{6.7}+...+\frac{1}{x\left(x+1\right)}=\frac{13}{90}\)

b,\(\frac{1}{1.4}+\frac{1}{4.7}+\frac{1}{7.10}+...+\frac{1}{x\left(x+3\right)}=\frac{49}{148}\)

c,\(\frac{7}{\left(x+3\right)\left(x+10\right)}+\frac{11}{\left(x+10\right)\left(x+21\right)}\)\(+\frac{1}{\left(x+21\right)\left(x+34\right)}=\frac{x}{\left(x+3\right)\left(x+34\right)}\)

d,\(\frac{3}{\left(x-4\right)\left(x-7\right)}+\frac{6}{\left(x-7\right)\left(x-13\right)}\)\(+\frac{15}{\left(x-13\right)\left(x-28\right)}\)\(-\frac{1}{x-38}=\frac{-1}{20}\)

thực hiện phép tính : ( tính nhanh nếu có thể )

a) \(\left(\frac{11}{12}:\frac{33}{16}\right).\frac{3}{5}+\frac{7}{23}.\left[\left(\frac{-8}{6}+\frac{-45}{18}\right)\right]\)

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

c) \(\frac{5}{9}:\left(\frac{1}{11}-\frac{5}{22}\right)+\frac{5}{9}:\left(\frac{1}{15}-\frac{2}{3}\right)\)

d) \(\frac{-3}{4}.\frac{12}{-5}.\frac{-25}{6}+\left(-2\right).\frac{-38}{21}.\frac{-7}{4}.\frac{-3}{8}\)

Bỏ ngoặc rồi tính :

a, \(\frac{6}{7}\) + \(\left(\frac{2}{11}-\frac{6}{7}\right)\)- \(\left(\frac{13}{11}+1\right)\)

b, \(\frac{-5}{11}\)- \(\left(\frac{17}{19}-\frac{5}{11}\right)\)- \(\left(\frac{17}{19}-2\right)\)

c, \(-\left(\frac{11}{14}-\frac{8}{9}\right)\)+ \(\left(\frac{-3}{14}-\frac{8}{19}\right)\)

d, \(\frac{3}{2}\) - \(\left[\left(\frac{-4}{7}\right)-\left(\frac{1}{2}+\frac{5}{8}\right)\right]\)

tìm x,biết:

a)\(\frac{2}{\left(x+2\right)\left(x+4\right)}+\frac{4}{\left(x+4\right)\left(x+8\right)}+\frac{6}{\left(x+8\right)\left(x+14\right)}=\frac{x}{\left(x+2\right)\left(x+14\right)}\)

b)\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)

c)\(\left(x+2\right)^2=\frac{38}{25}+\frac{9}{10}-\frac{11}{15}+\frac{13}{21}-\frac{15}{28}+\frac{17}{36}-...+\frac{197}{4851}-\frac{199}{4950}\)

giúp tớ với,huhu

Các bạn ơi ,giúp mình với

Bài 1:Rút gọn

a)\(\frac{2^{19}\times27^3+15\times4^9\times9^4}{6^9\times2^{10}+12^{10}}\)

b)\(\frac{\left(\frac{-1}{2}\right)^3-\left(\frac{3}{4}\right)^3\times\left(-2\right)^2}{2\times\left(-1\right)^5+\left(\frac{3}{4}\right)^2-\frac{3}{8}}\)

c)\(\frac{45\times9^4-2\times6^4}{2^{19}\times3^8+6^8\times20}\)

Bài 2:Tìm x

a)\(5^x+5^{x+2}=650\)

b)\(3^{x-1}+5\times3=162\)