Ta có: \(\left|97\dfrac{2}{3}-123\dfrac{3}{5}+97\dfrac{2}{5}-125\dfrac{1}{3}\right|\)
\(=\left|97\left(\dfrac{2}{3}+\dfrac{2}{5}\right)-125\cdot\left(\dfrac{3}{5}+\dfrac{1}{3}\right)\right|\)
\(=\left|194\cdot\dfrac{8}{15}-125\cdot\dfrac{14}{15}\right|\)
\(=\left|\dfrac{-66}{5}\right|=\dfrac{66}{5}\)
Tính:
a) S=1.2+2.3+3.4+...+99.100
b) B=\(\dfrac{49^{24}.125^{17}.2^8-5^{30}.7^{49}.4^5}{5^{29}.16^2.7^{48}}\)
c) C=\(\left(\dfrac{1}{3}+\dfrac{1}{3^2}+\dfrac{1}{3^3}+\dfrac{1}{3^4}\right).3^5+\left(\dfrac{1}{3^5}+\dfrac{1}{3^6}+\dfrac{1}{3^7}+\dfrac{1}{3^8}\right).3^9+...+\left(\dfrac{1}{3^{97}}+\dfrac{1}{3^{98}}+\dfrac{1}{3^{99}}+\dfrac{1}{3^{100}}\right).3^{101}\)
d) D= \(3-3^2+3^3-3^4+...+3^{2017}-3^{2018}\)
Tính
C=\(\dfrac{2^{12}\cdot3^5-4^6\cdot9^2}{\left(2^2\cdot3^6\right)^6+8^4\cdot3^5}-\dfrac{5^{10}\cdot7^3-25^5\cdot49^2}{\left(125\cdot7\right)^3+5^9\cdot14^3}\)
\(\left(z-\dfrac{2}{15}\right)^3=\dfrac{8}{125}\)
tìm x
a/ \(\dfrac{5^x}{125}\)= 25\(^4\) b/ \(\dfrac{3^x}{3}\)+ 3\(^{x-2}\) = 4
c/ (x + \(\dfrac{2006}{2007}\))\(^6\) =0 d/ (x-\(\dfrac{1}{5}\))\(^3\)= \(\dfrac{8}{125}\)
e/ 3\(^x\) + 3\(^{x-2}\)= 810 g/ 5\(^{x+2}\) +5\(^{x+1}\) +5\(^x\) = 19375
giúp mk nha các bn mk
tính giá trị biểu thức
\(\dfrac{6^2.6^3}{3^5}\)
\(\dfrac{25^2.4^2}{5^5.-2^5}\)
\(\dfrac{0,125^5.2,4^5}{-0,3^5.0,001^3}\)
\((2\dfrac{3}{4}+\dfrac{1}{2})\)
1 Tínha \(\left(\dfrac{5.5^3}{5^2.49}\right)^{15}:\left(\dfrac{5^6}{434}\right)^7\)
b \(\dfrac{49^{24}.125^{10}.2^8-5^{30}.7^{49}.4^5}{5^{29}.16^2.7^{48}}\)
làm nhanh giúp mik nha, chiều mai phải nộp rồi...thanks bn giúp mik nhiều lắm lun !!!
1. Tìm x biết:
a) \(\left(x+36\right)^2=1936\)
b) \(\dfrac{3}{5}^{x+2}=\dfrac{81}{625}\)
c) \(2005^{\left(2x-1\right)\left(2+3x\right)}=1\)
d) \(\left(\dfrac{9}{16}\right)^{x-5}=\left(\dfrac{4}{3}\right)^4\)
e) \(\left(\dfrac{3}{5}\right)^x.\left(\dfrac{125}{72}\right)^5=\dfrac{81}{625}\)
2. a) Tìm x biết:
\(\left(3x+1\right)^4=\left(3x-1\right)^2\)
b) Có số hữu tỉ x thõa mản đẳng thức
\(\left(3x+1\right)^4+\left(3x-1\right)^2=0\)
3. Tính giá trị của biểu thức:
\(A=\left\{-\left[-\left(\dfrac{1}{x}\right)^2\right]^3\right\}^5.\left\{-\left[-\left(-x\right)^5\right]^2\right\}^3\) ( \(x\notin0\)
4. Tìm các cặp số (x,y) thõa mản các đk sau:
a) \(x\left(x+y\right)=\dfrac{5}{12}\) và \(y\left(x+y\right)=\dfrac{5}{18}\)
b) \(x\left(x-y\right)=\dfrac{2}{45}\) và \(y\left(x-y\right)=\dfrac{1}{25}\)
Mai nộp rồi còn 4 bài đó ( help me )
K = \(\dfrac{1}{5}+\dfrac{2}{5^2}+\dfrac{3}{5^3}+\dfrac{4}{5^4}+\dfrac{5}{5^5}+...+\dfrac{100}{5^{100}}\)
Mình đang cần gấp!!!
Bài 1:Tính giá trị biểu thức
\(_{1,}\)\(3^2.\dfrac{1}{243}.81^2.\dfrac{1}{3^3}\)
\(_{2,}\)(\(4.2^5\)):\(\left(2^3.\dfrac{1}{16}\right)\)
\(_{3,}\)\(\left(2^{-1}+3^{-1}\right)+\left(2^{-1}.2^0\right):2^3\)
\(_{4,}\)\(\left(-\dfrac{1}{3}\right)^{-1}-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2:2\)
\(_{5,}\)[(0,1)\(^2\)]\(^0\)+[(\(\dfrac{1}{7}\))\(^{-1}\)]\(^2\).\(\dfrac{1}{49}.\left[\left(2^2\right)^3:2^5\right]\)
Bài 2:Rút gọn biểu thức
a,\(\dfrac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\)
b,\(\dfrac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}\)
c,\(\left(\dfrac{2}{5}\right)^7.5^7+\left(\dfrac{9}{4}\right)^3:\left(\dfrac{3}{16}\right)^3\)
\(\overline{2^7.5^2+512}\)
d,\(\left(\dfrac{2}{3}\right)^3.\left(-\dfrac{3}{4}\right)^2.\left(-1\right)^5\)
\(\overline{\left(\dfrac{2}{5}\right)^2}.\left(-\dfrac{5}{12}\right)^3\)
