\(\dfrac{-8^3\cdot6^4}{18^{12}}=\dfrac{2^3\cdot4^3\cdot2^2\cdot3^2}{2^{12}\cdot3^{12}\cdot3^{12}}\)
\(=\dfrac{2^5\cdot\left(2^2\right)^3\cdot3^2}{2^{12}\cdot3^{12}\cdot3^{12}}=\dfrac{2^6}{2^7\cdot3^{10}\cdot3^{12}}\)
\(=\dfrac{1}{2\cdot3^{22}}\)
1.rut gon phan so sau
a. \(\dfrac{-63}{81}\),\(\dfrac{5.6}{9.35}\),\(\dfrac{7.2+8}{2.14.5}\),\(\dfrac{9}{33-6}\),8
b.\(\dfrac{-270}{360}\),\(\dfrac{7}{10^2+6.10^2}\)
rut gon
a,3x(2x-7)-3x(4x-5)
b,(-7x+8)(-2x+3)-7x(2x-4)
c,(2x-3)(3x2-2x+4)-(2x-3)(3x+4)
d,(-2+7)(3x-6)-(4x-5)(2x-6)
1)Tính
a)-3/4 + 1\(\dfrac{1}{6}\) - 7/3= 0,2
b) -3\(\dfrac{1}{4}\) - 0,75 + 7/6 = 4/8
2)Tìm x
a) x+2/3=2/3-(-1/6)
b)| x+1/6|=11/12
3)So sánh các phân số sau bằn
a)-18/91 và -23/114
b)-22/35 và -103/177
Bài 5 : So sánh
a) A= \(\dfrac{a+1}{a+2}\) và B= \(\dfrac{a+2}{a+3}\)
b) C= \(\dfrac{8^9+12}{8^7+7}\) và D =\(\dfrac{8^{10}+4}{8^{10}-1}\)
Tính:
a) \(A=1+\dfrac{1}{2}\left(1+2\right)+\dfrac{1}{3}\left(1+2+3\right)+\dfrac{1}{4}\left(1+2+3+4\right)+...+\dfrac{1}{2013}\left(1+2+...+2013\right)\)b) \(B=\dfrac{1-3}{1\cdot3}+\dfrac{2-4}{2\cdot4}+\dfrac{3-5}{3\cdot5}+\dfrac{4-6}{4\cdot6}+...+\dfrac{2011-2013}{2011\cdot2013}+\dfrac{2012-2014}{2012\cdot2014}+\dfrac{2013-2015}{2013\cdot2015}\)Giúp mình với!
Soánh A và B
A=\(\dfrac{8^9+12}{8^9+7}\) và B=\(\dfrac{8^{10}+4}{8^{10}+1}\)
4, so sánh A và B:
a,A=\(\dfrac{3}{8^3}+\dfrac{7}{8^4}\);B=\(\dfrac{7}{8^3}+\dfrac{3}{8^4}\)
b,A=\(\dfrac{10^7+5}{10^7-8}\);B=\(\dfrac{10^8+6}{10^8-7}\)
c,A=\(\dfrac{10^{1992}+1}{10^{1991}+1}\);B=\(\dfrac{10^{1993}+1}{10^{1992}+1}\)
Tính :
a, \(\dfrac{3\cdot13-13\cdot18}{15\cdot40-80}\);
b, \(\dfrac{18\cdot34+\left(-18\right)\cdot124}{-36\cdot17+9\cdot\left(-52\right)}\);
c, \(\dfrac{\dfrac{3}{41}-\dfrac{12}{47}+\dfrac{27}{53}}{\dfrac{4}{41}-\dfrac{16}{47}+\dfrac{36}{53}}+\dfrac{-0,25\cdot\dfrac{-2}{3}-0,75:\left(\dfrac{-1}{2}+\dfrac{2}{3}\right)}{\left|-1\dfrac{1}{2}\right|\cdot\left(\dfrac{-2}{3}-75\%:\dfrac{3}{-2}\right)}\).
b) \(\dfrac{3}{y}< \dfrac{y}{7}< \dfrac{4}{y}\)
c) \(\dfrac{1}{8}< \dfrac{x}{18}< \dfrac{y}{24}< \dfrac{2}{9}\)
