Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a)\(\frac{5}{9}:\left(\frac{1}{11}-\frac{5}{22}\right)+\frac{5}{9}:\left(\frac{1}{15}-\frac{2}{3}\right)\)
\(=\frac{5}{9}:\left[\left(\frac{1}{11}-\frac{5}{22}\right)+\left(\frac{1}{15}-\frac{2}{3}\right)\right]\)
\(=\frac{5}{9}:\left[-\frac{3}{22}+-\frac{3}{5}\right]\)
\(=\frac{5}{9}:\frac{-81}{110}\)
\(=\frac{-550}{729}\)
Ta có:
\(\left(x-1\right).\left(x+1\right).\left(x+2\right)\)
\(=\left(x^2+x-x-1\right).\left(x+2\right)\)
\(=\left(x^2-1\right).\left(x+2\right)\)
\(=x^3+2x^2-x-2\)
\(\frac{\left(-4\right)^6.9^5-\left(-6\right)^9.120.1^{2015}}{8^4.3^{12}-6^{11}.2016^0}=\frac{\left(2^2\right)^6.\left(3^2\right)^5+\left(2.3\right)^9.2^3.3.5.1}{\left(2^3\right)^4.3^{12}-\left(2.3\right)^{11}.1}=\frac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)
\(=\frac{2^{12}.3^{10}.\left(1+5\right)}{2^{11}.3^{11}.\left(2.3-1\right)}=\frac{2.6}{3.5}=\frac{4}{5}\)
\(\frac{\left(-4\right)^6.9^5-\left(-6\right)^9.120.1^{2015}}{8^4.3^{12}-6^{11}.2016^0}=\frac{\left(-2\right)^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}-2^{11}.3^{11}}=\frac{2^{12}.3^{10}.\left(1+5\right)}{2^{11}.3^{11}.\left(2.3-1\right)}=\frac{2.6}{3.5}=\frac{4}{5}\)
\(\frac{2.2^{12}.3^6+2^2.2^9.3^9}{2^7.2^7.3^7.2^4.5.3^8}\)
\(=\frac{2^{13}.3^6+2^{11}.3^{^9}}{2^{18}.3^{15}.5}\)
\(=\frac{2^{11}.3^6\left(2^2+3^3\right)}{2^{11}.3^6.2^6.3^4.5}\)
\(=\frac{35}{2^6.3^4.5}\)
`(2 1/3 + 3 1/2): (-4 1/6 + 3 1/7) +7,5`
`=(7/3 +7/2) : (-25/6 + 22/7) + 15/2`
`=35/6 : (-43/42) + 15/2`
`=-245/43+15/2`
`=155/86`
\(A=1.2+2.3+3.4+...+99.100\)
\(3A=1.2.3+2.3.\left(4-1\right)+3.4.\left(5-2\right)+...+99.100.\left(101-98\right)\)
\(3A=99.100.101\)
\(A=33.100.101=333300\)
\(B=1^2+2^2+3^2+...+199^2\)
\(=1.2-1+2.3-2+3.4-3+...+199.200-199\)
\(=\left(1.2+2.3+3.4+...+199.200\right)-\left(1+2+3+...+199\right)\)
\(=\frac{199.200.201}{3}-\frac{\left(1+199\right).199}{2}\)
\(=2666600-19900=2646700\)
b, B = 1.2 + 2.3 + 3.4 + ... + 99.100
3B = 1.2.3 + 2.3.3 + 3.4.3 + ... + 99.100.3
3B = 1.2.3 + 2.3.(4 - 1) + 3.4.(5 - 2) + ... + 99.100.(101 - 98)
3B = 1.2.3 + 2.3.4 - 1.2.3 + 3.4.5 - 2.3.4 + ... + 99.100.101 - 98.99.100
3B = 99.100.101
B = 99.100.101 : 3
B = 333300
k mình đi rồi mình làm cho