a) 25. (-4) =?
(-12).12 =?
b) (-10) .11=?
137.(-15)=?
c) 24.(-25)=?
(-15).12=?
a.4^8.4^4
b.5^12 . 7-5^11 . 10
c.2^20 . 15+2^10 . 85
d.27^16 : 9^10
e.125^3 :25^4
f.24^4 : 3^4 - 32^12: 16^12
Mình cần gấp ạ
a) \(4^8\cdot4^4=\left(2^2\right)^8\cdot\left(2^2\right)^4=2^{16}\cdot2^8=2^{16+8}=2^{24}\)
b) \(5^{12}\cdot7-5^{11}\cdot10\)
\(=5^{11}\cdot\left(5\cdot7-10\right)=5^{11}\cdot\left(35-10\right)=5^{11}\cdot25\)
\(=5^{11}\cdot5^2=5^{11+2}=5^{13}\)
d) \(27^{16}:9^{10}\)
\(=\left(3^3\right)^{16}:\left(3^2\right)^{10}=3^{48}:3^{20}=3^{48-20}=3^{28}\)
e) \(125^3:25^4=\left(5^3\right)^3:\left(5^2\right)^4=5^9:5^8=5^{9-8}=5\)
f) \(24^4:3^4-32^{12}:16^{12}\)
\(=\left(24:4\right)^4-\left(32:16\right)^{12}\)
\(=6^4-2^{12}\)
\(=2^4\cdot\left(3^4-2^8\right)=2^4\cdot-175=-2800\)
Quy đồng các phân số sau:
A) 7/9 và 8/11
b) 4/5 và 7/25
c) 25/96 và 16/12
d) 1/5 , 6/10 và 12/30
e) 5/6, 7,3 và 15/24
a, \(\dfrac{7}{9}\) = \(\dfrac{7\times11}{9\times11}\) = \(\dfrac{77}{99}\)
\(\dfrac{8}{11}\) = \(\dfrac{8\times9}{11\times9}\) = \(\dfrac{72}{99}\)
Vậy \(\dfrac{7}{9}\) và \(\dfrac{8}{11}\) đã được quy đồng mẫu số lần lượt thành hai phân số:
\(\dfrac{77}{99}\) và \(\dfrac{72}{99}\)
b, \(\dfrac{4}{5}\) = \(\dfrac{4\times5}{5\times5}\) = \(\dfrac{20}{25}\)
Vậy hai phân số \(\dfrac{4}{5}\) và \(\dfrac{7}{25}\) đã được quy đồng mẫu số thành hai phân số: \(\dfrac{20}{25}\) và \(\dfrac{7}{25}\)
c, \(\dfrac{25}{96}\) và \(\dfrac{16}{12}\)
\(\dfrac{25}{96}\) = \(\dfrac{25}{96}\);
\(\dfrac{16}{12}\) = \(\dfrac{16\times8}{12\times8}\) = \(\dfrac{128}{96}\)
Vậy hai phân số \(\dfrac{25}{96}\) và \(\dfrac{16}{12}\) đã được quy đồng mẫu số thành hai phân số: \(\dfrac{25}{96}\) và \(\dfrac{128}{96}\)
1.tính A.-5/8-7/-12 B.3/4+(-5)/6-11/-12 C.1/6-1/36 D.15/48-(-5)/12 E.-1/7-1/8 F.-5/15-(-3)/25 G.3/4-(-5)/12-7/-24
a: \(=\dfrac{-5}{8}+\dfrac{7}{12}=\dfrac{-15}{24}+\dfrac{14}{24}=\dfrac{-1}{24}\)
b: \(=\dfrac{3}{4}-\dfrac{5}{6}+\dfrac{11}{12}=\dfrac{9}{12}-\dfrac{10}{12}+\dfrac{11}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)
c: \(=\dfrac{6}{36}-\dfrac{1}{36}=\dfrac{5}{36}\)
d: \(=\dfrac{5}{12}+\dfrac{5}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)
e: \(=\dfrac{-8}{56}-\dfrac{7}{56}=\dfrac{-15}{56}\)
f: \(=\dfrac{-5}{15}+\dfrac{3}{25}=\dfrac{-25}{75}+\dfrac{9}{75}=\dfrac{-16}{75}\)
bài 1: tính hợp lí
a) 5 x 72 x 10 x 2 b) 40 x 125 c) 4 x 2021 x 25 d) 16 x 6 x 25
bài 2: tính nhanh
a) 24 x 57 + 43 x 24 b) 12 x 19 + 80 x 12 +12
c) (36 x 15 x 169) : (5 x 18 x13) d) (44 x 52 x 60) : ( 11 x 13 x 15)
bài 3: tìm X
a) X - 280 : 35 = 5 x 54 b) ( X - 280) : 35 = 54 : 4
c) ( X - 128 + 20 ) : 192 = 0 d) 4 x ( X + 200) = 460 + 85 x 4
bài 4: thực hiện phép tính
a) 7/12 - 5/12 b) 8/11 + 19/11 c) 3/8 + 5/12 d) 3/4 + 7/12
bài 5: tìm x
a) X - 6/7 = 5/2 b) 12/7 : X + 2/3 = 7/5
Bài 1
a) \(5\times72\times10\times2=\left(5\times2\times10\right)\times72=100\times72=7200\)
b) \(40\times125=5\times\left(8\times125\right)=5\times1000=5000\)
c) \(16\times6\times25=4\times4\times6\times25=\left(4\times6\right)\times\left(4\times25\right)=24\times100=2400\) Bài 2:
a) \(24\times57+43\times24=24\times\left(57+43\right)=24\times100=2400\)
b) \(12\times19+80\times12+12=12\times\left(19+80+1\right)=12\times100=1200\)
c) \(\left(36\times15\times169\right)\div\left(5\times18\times13\right)\)
\(=\left(18\times2\times3\times5\times13\times13\right)\div\left(5\times18\times13\right)\)
\(=\left(2\times3\times13\right)\times\left(18\times5\times13\right)\div\left(5\times18\times13\right)\)
\(=2\times3\times13\)
\(=78\)
d) \(\left(44\times52\times60\right)\div\left(11\times13\times15\right)\)
\(=\left(4\times11\times4\times13\times4\times15\right)\div\left(11\times13\times15\right)\)
\(=\left(4\times4\times4\right)\times\left(11\times13\times15\right)\div\left(11\times13\times15\right)\)
\(=4\times4\times4\)
\(=64\)
Bài 3:
a) \(x-280\div35=5\times54\)
\(x-8=270\)
\(x=270+8\)
\(x=278\)
b) \(\left(x-280\right)\div35=54\div4\)
\(\left(x-280\right)\div35=\dfrac{27}{2}\)
\(x-280=\dfrac{27}{2}\times35\)
\(x-280=\dfrac{945}{2}\)
\(x=\dfrac{945}{2}+280\)
\(x=\dfrac{1505}{2}\)
c) \(\left(x-128+20\right)\div192=0\)
\(x-128+20=0\times192\)
\(x-128+20=0\)
\(x-128=0-20\)
\(x-128=-20\)
\(x=-20+128\)
\(x=108\)
d) \(4\times\left(x+200\right)=460+85\times4\)
\(4\times\left(x+200\right)=460+340\)
\(4\times\left(x+200\right)=800\)
\(x+200=800\div4\)
\(x+200=200\)
\(x=200-200\)
\(x=0\)
Bài 4:
a) \(\dfrac{7}{12}-\dfrac{5}{12}=\dfrac{2}{12}=\dfrac{1}{6}\)
b) \(\dfrac{8}{11}+\dfrac{19}{11}=\dfrac{27}{11}\)
c) \(\dfrac{3}{8}+\dfrac{5}{12}=\dfrac{9}{24}+\dfrac{10}{24}=\dfrac{19}{24}\)
d) \(\dfrac{3}{4}+\dfrac{7}{12}=\dfrac{9}{12}+\dfrac{7}{12}=\dfrac{16}{12}=\dfrac{4}{3}\)
Bài 5:
a) \(x-\dfrac{6}{7}=\dfrac{5}{2}\)
\(x=\dfrac{5}{2}+\dfrac{6}{7}\)
\(x=\dfrac{47}{14}\)
b) \(\dfrac{12}{7}\div x+\dfrac{2}{3}=\dfrac{7}{5}\)
\(\dfrac{12}{7}\div x=\dfrac{7}{5}-\dfrac{2}{3}\)
\(\dfrac{12}{7}\div x=\dfrac{11}{15}\)
\(x=\dfrac{12}{7}\div\dfrac{11}{15}\)
\(x=\dfrac{180}{77}\)
mọi người ơi pls help me
1) -10/11 . 8/9 + 7/18 . 10/11 2) 12/25 . 23/7 - 12/7 . 13/25 3) 3/7 . 16/15 - 2/15 . -3/7 4) -4/13 . 5/17 + -12/13 . 4/17
\(1)\)\(-\dfrac{10}{11}.\dfrac{8}{9}+\dfrac{7}{18}.\dfrac{10}{11}\)
\(=\dfrac{10}{11}\left(-\dfrac{8}{9}+\dfrac{7}{18}\right)\)
\(=\dfrac{10}{11}\left(\dfrac{-16}{18}+\dfrac{7}{18}\right)\)
\(=\dfrac{10}{11}.\left(-\dfrac{1}{2}\right)=-\dfrac{5}{11}\)
\(2)\)\(\dfrac{12}{25}.\dfrac{23}{7}-\dfrac{12}{7}.\dfrac{13}{25}\)
\(=\dfrac{12}{7}.\dfrac{23}{25}-\dfrac{12}{7}.\dfrac{13}{25}\)
\(=\dfrac{12}{7}.\left(\dfrac{23}{25}-\dfrac{13}{25}\right)\)
\(=\dfrac{12}{7}.\dfrac{2}{5}=\dfrac{24}{35}\)
\(3)\)\(\dfrac{3}{7}.\dfrac{16}{15}-\dfrac{2}{15}.\dfrac{-3}{7}\)
\(=\dfrac{3}{7}.\dfrac{16}{15}-\dfrac{3}{7}.\dfrac{-2}{15}\)
\(=\dfrac{3}{7}.\left(\dfrac{16}{15}+\dfrac{2}{15}\right)\)
\(=\dfrac{3}{7}.\dfrac{18}{15}=\dfrac{18}{35}\)
\(4)\)\(-\dfrac{4}{13}.\dfrac{5}{17}+\dfrac{-12}{13}.\dfrac{4}{17}\)
\(=-\dfrac{4}{13}.\dfrac{5}{17}+\dfrac{-4}{13}.\dfrac{12}{17}\)
\(=-\dfrac{4}{13}.\left(\dfrac{5}{17}+\dfrac{12}{17}\right)\)
\(=-\dfrac{4}{13}.\dfrac{17}{17}=-\dfrac{4}{13}\)
`#040911`
`1)`
`-10/11 * 8/9 + 7/18 . 10/11`
`= 10/11 * (-8/9 + 7/18)`
`= 10/11 * (-1/2)`
`= -5/11`
`2)`
`12/25 * 23/7 - 12/7 *13/25`
`= 12/7 * 23/25 - 12/7 * 13/25`
`= 12/7 * (23/25 - 13/25)`
`= 12/7 * 2/5`
`= 24/35`
`3)`
`3/7 * 16/15 - 2/15 * (-3)/7`
`= 3/7 * (16/15 + 2/15)`
`= 3/7 * 6/5`
`= 18/35`
`4)`
`-4/13 * 5/17 + (-12)/13 * 4/17`
`= -4/17 * 5/13 + (-12)/13 * 4/17`
`= 4/17 * (-5/13 - 12/13)`
`= 4/17 * (-17)/13`
`= -4/13`
Tính nhanh:A=1*5*6+2*10*12+3*15*18+4*20*24+5*25*30/1*3*5+2*6*10+3*9*15+4*12*20+5*15*25
ta có : (ghi lại đề)
=6+12+18+24+30/3+6+9+12+15
=2*(3/3+6/6+9/9+12/12+15/15)
=2*(1+1+1+1+1)
=2*5=10
chúc main học tốt nhé
a -5/9 + ( 17/20 - 4/9 ) b (7/15 - 11/20 ). -25/3 c ( 5/6 - 1/2 ).(8/15 - 3/15) d 11/12 + 7/16 : -3/4 - 13/12 giup mimh voi minh tich cho
a: =-1+17/20=-3/20
b: =(28/60-33/60)*(-25/3)
=(-1/12)*(-25/3)=1/12*25/3=25/36
c: \(=\dfrac{1}{3}\cdot\dfrac{1}{3}=\dfrac{1}{9}\)
Cho các phân số: 9/12; 15/16; 18/25; 24/36; 17/25.
Các phân số = 3/4 là:
a]. 9/12; 15/20; 24/36; 17/25. b]. 19/12; 18/25; 24/36; 17/25.
c]. 9/12; 15/20; 24/36. d]. 9/12; 15/20; 18/25; 24/36.
a] hay b] hay c] hay d].
Bạn ghi kiểu gì mình không hiểu
Không có cái nào đúng
Phần c có 24/36=2/3 mà bạn bạn sai rồi
Rút gọn :
a/ 5^2 . 6^11 . 16^2 + 6^2 . 12^6 . 15^2 / 2. 6^12. 10^4 - 81^2 . 960^3
b/ 25^28+ 25^24 +...+ 25^24+1 / 25^30 +25^28 + ...+ 25^2 + 1
Nhớ tất cả đều là phân số nhé các bạn
Mình rất mong được sự ủng hộ của các bạn và giáo viên hoc24h
huhu ... hoh có ai giúp mình cả 30 Tết mình phải nộp cho thầy rùi . Sợ quá . Sợ nhất là cây thước gỗ của thầy
Vậy là vượt qua thời khắc kinh khủng nhất rùi . Ahihi
a: \(=\dfrac{5^2\cdot2^{19}\cdot3^{11}+2^2\cdot3^2\cdot2^{12}\cdot3^6\cdot3^2\cdot5^2}{2^{13}\cdot3^{12}\cdot2^4\cdot5^4-3^8\cdot2^{18}\cdot3^3\cdot5^3}\)
\(=\dfrac{5^2\cdot2^{19}\cdot3^{11}+5^2\cdot2^{14}\cdot3^{10}}{5^4\cdot2^{17}\cdot3^{12}-5^3\cdot3^{11}\cdot2^{18}}\)
\(=\dfrac{5^2\cdot2^{14}\cdot3^{10}\left(2^5\cdot3+1\right)}{5^3\cdot2^{17}\cdot3^{11}\left(5-2\right)}=\dfrac{1}{5\cdot8\cdot3}\cdot\dfrac{97}{3}=\dfrac{97}{360}\)
b: \(=\dfrac{25^{28}+25^{24}+...+25^{24}+1}{25^{28}+25^{24}+...+1+25^{30}+25^{36}+...+25^2}\)
\(=\dfrac{1}{1+25^2}=\dfrac{1}{626}\)