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=\(\dfrac{20}{39}+\dfrac{22}{27}+\dfrac{18}{43}\) B=\(\dfrac{14}{39}+\dfrac{22}{29}+\dfrac{18}{41}\)
So sánh
a) \(\dfrac{17}{30}\)và \(\dfrac{51}{92}\)
b) \(-\dfrac{45}{47}\)và \(\dfrac{31}{-30}\)
c) \(\dfrac{22}{67}\)và \(\dfrac{51}{152}\)
d) \(-\dfrac{17}{39};\dfrac{18}{-39}\)và \(-\dfrac{17}{41}\)
e) \(\dfrac{42}{-37}\)và \(-\dfrac{56}{43}\)
Rút gọn phân số \(\dfrac{9^{20}.2^{27}.22^5}{4^8.18^{18}.33^4}\). Ta đc phân số tối giản là \(\dfrac{a}{4}\). a = ?
So Sánh : S = \(\dfrac{1}{5}+\dfrac{1}{9}+\dfrac{1}{10}+\dfrac{1}{41}+\dfrac{1}{42}\) và \(\dfrac{1}{2}\)
Tìm số nguyên x, nếu biết
a, \((\dfrac{1}{2}-\dfrac {1}{6})3^x +3^{x+2}= 3^{16}+3^{13}\)
b, \((\dfrac {1}{2}-\dfrac{1}{3}).6^x +6^{x+2}= 6^{15}+6^{18}\)
c, \((\dfrac{1}{3}+\dfrac{1}{6})2^{x+3} -2^x = 2^{22}-2^{20}\)
4. thực hiện phép tính
a.\(\dfrac{4}{9}+\dfrac{11}{125}-\dfrac{17}{18}+\dfrac{17}{14}-\dfrac{5}{7}\)
b. \(1-\dfrac{1}{2}+2-\dfrac{2}{3}+3-\dfrac{3}{4}+4-\dfrac{1}{4}-3-\dfrac{1}{3}-2-\dfrac{1}{2}-1\)
c.\(\dfrac{1}{3}.\dfrac{14}{25}-\dfrac{1}{2}:\dfrac{25}{14}\)
d. \(\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{4}{7}-\dfrac{18}{13}\)
cho \(x=\dfrac{\left(\dfrac{3}{10}-\dfrac{4}{15}-\dfrac{7}{20}\right).\dfrac{5}{19}}{\left(\dfrac{1}{14}+\dfrac{1}{7}+\dfrac{3}{35}\right).\dfrac{-4}{3}}\) . Tính \(P=\sqrt{120x+39}\)
So Sanh : \(\dfrac{-22}{45}\)và\(\dfrac{-51}{103}\)
1. So sánh các tích sau hợp lý nhất:
P = \(\left(-\dfrac{21}{34}\right)\)\(\left(-\dfrac{13}{27}\right)\)\(\dfrac{7}{9}\)
Q = \(\left(-0,5\right)\)\(\dfrac{3}{19}\)\(\left(-\dfrac{24}{41}\right)\)\(\left(\dfrac{8}{31}\right)\)
M = \(\dfrac{-6}{17}.\dfrac{-5}{17}.\) ... \(.\dfrac{5}{17}.\dfrac{6}{17}\)
2. Tính hợp lý:
A = \(\left(-\dfrac{3}{11}\right).\dfrac{7}{10}.\dfrac{11}{-13}.\left(-20\right)\)
B = \(\dfrac{-4}{9}:\dfrac{2}{13}+\left(\dfrac{-5}{18}\right).\dfrac{2}{13}\)
C = \(\left(2\dfrac{1}{15}.\dfrac{3}{19}.\dfrac{2}{31}\right):\left(-\dfrac{5}{19}\right)\)
Help me!