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a) \(\frac{25.9-25.17}{-8.80-8.10}=\frac{25.\left(9-17\right)}{-8.\left(80+10\right)}=\frac{25.\left(-8\right)}{-8.90}=\frac{5}{18}\)
b) \(\frac{48.12-48.15}{-3.270-3.30}=\frac{48.\left(12-15\right)}{-3.\left(270+30\right)}=\frac{48.\left(-3\right)}{-3.300}=\frac{4}{25}\)
c) \(\frac{2^5.7+2^5}{2^5.5^2-2^5.3}=\frac{2^5.\left(7+1\right)}{2^5.\left(5^2-3\right)}=\frac{2^5.8}{2^5.\left(25-3\right)}=\frac{2^5.8}{2^5.22}=\frac{4}{11}\)
d) \(\frac{3^4.5-3^6}{3^4.13+3^4}=\frac{3^4.\left(5-3^2\right)}{3^4.\left(13+1\right)}=\frac{3^4.\left(5-9\right)}{3^4.14}=\frac{3^4.\left(-4\right)}{3^4.14}=\frac{-2}{7}\)
\(A=\dfrac{2^4.3^3+2^3.3^4}{2^5.3^4-2^6.3^3}=\dfrac{2^3.3^3.\left(2+3\right)}{2^5.3^3.\left(3-2\right)}=\dfrac{2^3.3^3.5}{2^5.3^3.1}\)
\(=\dfrac{5}{2^2}=\dfrac{5}{4}\)
a , 5.6 + 5.7 / 5.8 + 20 = 5.6 + 5.7 / 5.8 + 5 . 4 = 5 . ( 6+7 ) / 5 . ( 8 + 4 ) = 6 + 7 / 8 + 4 = 13 / 12 8 . 9 + 4 .15 / 12 . 7 - 180 = 4 . 2 . 3 . 3 + 2 . 2 . 3 . / 4 . 3 . 7 - 180 = 4 . 2 . 3 . 3 + 2.2.3.5 / 3 . 4 . 7 - 3 . 2 . 2 . 3. 5 = 1 . 2 . 1 . 1 + 1 . 1 . 1. 1 / 1 . 1 . 7 - 1 . 1 . 1 . 1 .1 = 3 / 6 = 1/2 b , 2^5 . 7 +2^5 / 2^5 . 5^2 - 2^5 .3 = 2^5 . ( 7 + 1) / 2^5 ( 5^2 - 3 ) = 7+1 / 5^2 - 3 = 8 / 22 = 4 / 11 3^4 . 5 - 3^6 / 3^4 . 13 + 3^4 = 3^4 . 5 - 3^4 . 3^2 / 3^4 . 13 + 3^4 = 3^4 . ( 5 - 3^2 ) / 3^4 . ( 13 + 1 ) = 5 - 3^2 / 13 + 1 = -4 / 14 = -2 / 12
a)2.3.5.13/26.35
=2.3.5.13/2.13.5.7
=3/7
b)18.6-18/-36.(-35)
=18.6-18/-(36.25)=18(6-1)/-(36.35)
=18.5/-(36.35)=2.3.3.5/-(2.2.3.3.5.7)
=-1/14
c)6.4+6.7/6.5+12=6.4+6.7/6.5+6.2
=6(4+7)/6(5+2)
=11/10
d)25.9-25.17/-8.80-8.10=25(9-17)/8(-80-10)
=25.(-8)/8(-90)
=5/18
e) 34.5-36/34.13-34
=34(5-32)/34(13-1)
=5-32/13-1=-1/3
Bài 1:
\(\left(-\dfrac{72}{40}-\dfrac{144}{60}-2\dfrac{1}{3}\right):\left(\dfrac{45}{100}-\dfrac{25}{60}+-\dfrac{75}{25}\right)\)
\(=\left(-\dfrac{9}{5}-\dfrac{12}{5}-\dfrac{7}{3}\right):\left(\dfrac{9}{20}-\dfrac{5}{12}+-3\right)\)
\(=\left(-\dfrac{27}{15}-\dfrac{36}{15}-\dfrac{21}{15}\right):\left(\dfrac{27}{60}-\dfrac{25}{60}+-3\right)\)
\(=\left(-\dfrac{28}{5}\right):\left(-\dfrac{89}{30}\right)\)
\(=\left(-\dfrac{28}{5}\right).\left(-\dfrac{30}{89}\right)\)
\(=\dfrac{168}{89}\)
đây là tính nhanh à nếu tính bình thường thì tính may tính là ra
a) 17/23 . 8/16 . 23/17. (-80) . 3/4
= (17/23 . 23/17) . (8/16 . 3/4) . (-80)
= 1 . 3/8 . (-80)
= 3/8 . (-80)
= -30
b) 5/11 . 18/29 - 5/11 . 8/29 + 5/11 . 19/29
= 5/11 . (18/29 - 8/29 + 19/29)
= 5/11 . 1
= 5/11
c)(13/23 + 1313/2323 - 131313/232323).(1/3+1/4 -7/12)
= (13/23 + 1313/2323 - 131313/232323).0
= 0
d) 12/2x2 . 22/2x3 . 32/3x4 . 42/4x5 . 52/5x6 . 62/6x7 . 72/7x8 . 82/8x9 . 92/9x10
= 1/2 . 2/3 . 3/4 . 4/5 . 5/6 . 6/7 . 7/8 . 8/9 .9/10
= 1/10
Khó nhìn quá. Bạn thông cảm nhé! 
\(1,\)
\(\dfrac{45^2.3^8.10^5}{5^5.3^7.18^5}\)
\(=\dfrac{3^4.5^2.3^8.2^5.5^5}{5^5.3^7.2^5.3^{10}}\)
\(=\dfrac{3^{12}.2^5.5^7}{5^5.3^{17}.2^5}\)
\(=\dfrac{1.5^2}{3^5.1}\)
\(=\dfrac{25}{243}\)
\(2,\)
\(\dfrac{4^5.9^4+2.6^9}{2^{10}.3^8+6^8.20}\)
\(=\dfrac{2^{10}.3^8+2.2^9.3^9}{2^{10}.3^8+2^8.3^8.2^2.5}\)
\(=\dfrac{2^{10}.3^8+2^{10}.3^9}{2^{10}.3^8+2^{10}.3^8.5}\)
\(=\dfrac{2^{10}.3^8.4}{2^{10}.3^8.6}\)
\(=\dfrac{2^{12}.3^8}{2^{11}.3^9}\)
\(=\dfrac{2}{3}\)
\(3,\)
\(\dfrac{15.3^{11}+4.27^4}{9^7}\)
\(=\dfrac{3.5.3^{11}+2^2.3^{12}}{3^{14}}\)
\(=\dfrac{5.3^{12}+2^2.3^{12}}{3^{14}}\)
\(=\dfrac{3^{12}\left(5+2^2\right)}{3^{14}}\)
\(=\dfrac{3^{12}.9}{3^{14}}\)
\(=\dfrac{3^{14}}{3^{14}}\)
\(=1\)
\(4,\)
\(\dfrac{4^7.2^8}{3.2^{15}.16^2-5^2\left(2^{10}\right)^2}\)
\(=\dfrac{2^{22}}{3.2^{23}-5^2.2^{20}}\)
\(=\dfrac{2^{22}}{2^{20}.\left(-1\right)}\)
\(=\dfrac{2^{22}}{-2^{20}}\)
\(=-4\)
* Mấy bài còn lại tương tự đấy bạn tự làm đi
Mình mỏi tay lắm rồi
P/s:khuyến khích tự làm,chỉ làm mẫu 1 câu:
1)\(\dfrac{45^2.3^8.10^5}{5^5.3^7.18^5}=\dfrac{\left(5.9\right)^2.3.3^7.\left(2.5\right)^5}{5^5.3^7.\left(2.9\right)^5}\)\(=\dfrac{5^2.9^2.3.3^7.2^5.5^5}{5^5.3^7.2^5.9^5}\)\(=\dfrac{5^2.9^2.3.1.1.1}{1.1.1.9^5}\)\(=\dfrac{5^2.9^2.3}{9^5}=\dfrac{5^2.9^2.3}{9^2.9^3}=\dfrac{5^2.3}{9^3}=\dfrac{75}{729}=\dfrac{25}{243}\)
a: \(\dfrac{25\cdot9-25\cdot17}{-8\cdot80-8\cdot10}=\dfrac{25\cdot\left(-8\right)}{\left(-8\right)\cdot\left(80+10\right)}=\dfrac{25}{90}=\dfrac{5}{18}=\dfrac{250}{900}\)
\(\dfrac{48\cdot12-48\cdot15}{\left(-3\right)\cdot\left(270+30\right)}=\dfrac{48}{300}=\dfrac{8}{50}=\dfrac{144}{900}\)
\(\dfrac{2^5\cdot3}{600}=\dfrac{96}{600}=\dfrac{144}{900}\)
b: \(\dfrac{2^5\cdot7+25}{25\cdot5^2-2^5\cdot3}=\dfrac{32\cdot7+25}{25\cdot25-32\cdot3}=\dfrac{249}{529}=\dfrac{1743}{7\cdot529}\)
\(\dfrac{3^4\cdot5-3^6}{3^4\cdot13+3^4}=\dfrac{3^4\left(5-9\right)}{3^4\left(13+1\right)}=\dfrac{-4}{14}=\dfrac{-2}{7}=\dfrac{-1058}{7\cdot529}\)