Ta thấy A gấp 12+22+....+102 4 lần nên Tổng A gấp 4 lần nó
=> A=385.4=1540
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Đại số lớp 7
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Rút gọn
C = \(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{9}{4}\right)^3:\left(\frac{3}{16}\right)^3}{2^7.5^2+512}\)
D = \(\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}\)
E = \(\frac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
Bài 1 tính .a) dfrac{left(-3right)^{10}.15^5}{25^3.left(-9right)^7}b) 2^3 +3 . (dfrac{1}{9})^0 -2^{-2} . 4 +[ (-2)^2 : dfrac{1}{2} ] . 8Giúp mình với mình cảm ơn
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Bài 1 tính .
a) \(\dfrac{\left(-3\right)^{10}.15^5}{25^3.\left(-9\right)^7}\)
b) 2\(^3\) +3 . (\(\dfrac{1}{9}\))\(^0\) -2\(^{-2}\) . 4 +[ (-2)\(^2\) : \(\dfrac{1}{2}\) ] . 8
Giúp mình với mình cảm ơn
Bài 1
a) thực hiện phép tính A=\(\frac{2^{12}\times3^5-4^6\times9^2}{\left(2^2\times3\right)^6+8^4\times3^5}-\frac{5^{10}\times7^3+25^5\times49^2}{\left(125\times7\right)^3+5^9\times14^3}\)
b) CMR: Với mọi số nguyên dương n thì:\(3^{n+2}-2^{n+2}+3^n-2^n\) chia hết cho 10
8) \(\dfrac{17}{-26}.\left(\dfrac{1}{6}-\dfrac{5}{3}\right):\dfrac{17}{13}-\dfrac{20}{3}.\left(\dfrac{2}{5}-\dfrac{1}{4}\right)+\dfrac{2}{3}.\left(\dfrac{6}{5}-\dfrac{9}{2}\right)\)
5. \(3-1\dfrac{1}{2}-x+\dfrac{5}{4}=2-\left|1\dfrac{1}{8}-\dfrac{5}{12}\right|\) 6. \(3\dfrac{1}{14}-5\dfrac{1}{3}-\dfrac{4}{7}+\dfrac{11}{21}=-\dfrac{1}{2}\) 7. \(\dfrac{11}{-40}+\dfrac{4}{5}-\left|\dfrac{3}{4}-1\dfrac{5}{12}\right|=\dfrac{3}{20}-X\)
A = \(\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}\) _\(\frac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
5. \(3-1\dfrac{1}{2}-x+\dfrac{5}{4}=2-\left|1\dfrac{1}{8}-\dfrac{5}{12}\right|\) 6. \(3\dfrac{1}{14}-5\dfrac{1}{3}-\dfrac{4}{7}+\dfrac{11}{21}=x-\dfrac{1}{2}\) 7. \(\dfrac{11}{-40}+\dfrac{4}{5}-\left|\dfrac{3}{4}-1\dfrac{5}{12}\right|=\dfrac{3}{20}-x\)
Chung minh rang:
a/ 36^20-9^10 : 405
b/ 8^12-2^33-2^30 : 55
c/ 8^7-2^18 :14
d/ 10^6-5^7 ;59
Thực hiện phép tính:
a,\(\frac{15}{33}+\frac{7}{20}+\frac{18}{33}+\frac{13}{20}\)
b, \(2\frac{1}{2}+\frac{4}{7}:\left(\frac{-8}{21}\right)\)
c, \(\left(\frac{-1}{2}\right)^3+\frac{1}{2}:5\)