tính nhanh
g))\(\frac{2^{10}.3^{11}+2^{10}.3^6}{2^{11}.3^{11}+2^{11}.3^6}\)
i) -3,15.(-7,2) + (-3,15).12,4 - 4,8 . 3,15 =
Tính nhanh :
i) -3,15 . ( - 7,2 ) + ( -3,15 ) .12,4 - 4,8 . 3,15=
=(-3,15).\(\left[\left(-7,2\right)+12,4-4,8\right]\)
=(-3,15).0,4
=-1,26
Tìm x biết:
a, \(\frac{x}{3,15}=\frac{0,15}{7,2}\)
b, \(\frac{-2,6}{x-11}=\frac{-12}{42}\)
c, \(3\frac{4}{5}:2x=0,25:2\frac{2}{3}\)
\(a.\) \(\frac{x}{3.15}\) \(=\) \(\frac{0.15}{7.2}\)
<=> \(x=\) \(\frac{0.15\cdot3.15}{7.2}\)
<=>\(x=0.065625\)
\(b.\) \(\frac{-2.6}{x-11}=\frac{-12}{42}\)
<=>\(x-11=\frac{-2.6\cdot-12}{42}\)
<=>\(x-11=0.742857142\)
<=>\(x=11.74285714\)
\(3\frac{4}{5}:2x=0,25:2\frac{2}{3}\)
\(\Leftrightarrow\frac{19}{5}:2x=0,25:\frac{8}{3}\)
\(\Leftrightarrow\frac{19}{5}:2x=0,25\cdot\frac{3}{8}\)
\(\Leftrightarrow\frac{19}{5}:2x=\frac{3}{32}\)
\(\Leftrightarrow2x=\frac{19}{5}:\frac{3}{32}=\frac{19}{5}\cdot\frac{32}{3}=\frac{608}{15}\)
\(\Leftrightarrow x=\frac{608}{15}:2=\frac{608}{30}=\frac{304}{15}\)
Tìm các số hữu tỉ x trong các tỉ lệ thức
a) 0,4 : x = x : 0,9
b) 0,2 : 1 1/5 = 2/3 : (6x + 7)
c) 13 1/3 : 1 1/3 = 26 : (2x + 1)
d) 37 - x/x + 13= 3/7
e) 3x + 2/5x + 7= 3 x - 1/5x + 1
h) x / 3,15 = 0,15 / 7,2
i) -2,6/x = -12/42
K) 11/10,5 = 6,32
L) 41/10//9/4= x/ 7,3
Tính theo cách hợp lí :
a) 4,25+3,15+3,75+5,85
b)\(\left(\frac{3}{5}+\frac{4}{7}\right)+\frac{2}{5}\)
c)6,24+5,36+3,76
d)\(\left(\frac{19}{15}+\frac{3}{5}\right)+\frac{11}{15}\)
a)4,25+3,15+3,75+5,85=(4,25+3,75)+(3,15+5,85)=8+9=17.
b)(3/5+4/7)+2/5=(3/5+2/5)+4/7=1+4/7=11/7.
c)6,24+5,36+3,76=(6,24+3,76)+5,36=10+5,36=15,36.
d)(19/15+3/5)+11/15=(19/15+11/15)+3/5=2+3/5=13/5.
ủng hộ nha có j kb vs mk
Tính bằng cách thuận tiện nhất:
a ) 4,25 + 3,15 + 3,75 + 5,85
= ( 4,25 + 3,75 ) + ( 3,15 + 5, 85 )
= 8 + 9
= 17
tks giúp mk vs ạ!
a) 4,25 + 3,15 + 3,75 + 5,85 = ( 4,25 + 3,75 ) + ( 3,15 + 5,85 ) = 8 + 9 = 17
b) (3/5 + 4/7) + 2/5 = (3/5 + 2/5) + 4/7 = 1 + 4/7 = 7/7 + 4/7 = 11/7
c) 6,24 + 5,36 + 3,76 = (6,24 + 3,76) + 5,36 = 10 + 5,36 = 15,36
d) (19/15 + 3/5) + 11/15 = (19/15 + 11/15) + 3/5 = 2 + 3/5 = 10/5 + 3/5 = 13/5
thực hiện phép tính :
a) 15/4:(1/8-7/16)-5/9.(3/5-(-12)/15)
b) 3/32-7/34-3,15+4/11+12/17
c) 1/5-3,5-3/2+1,25
d)12/17.(1-1/15)-12/17.(4/5-1)
e) 2,15:8/9-7/4:8/9+(-5/6)^2
f) 5/6 :-1/2+5/6:-1/4+2,3
g) (1/2-2/3)^2 : (-0,5)^2 : (-0,5)^2 + (1,25-3/2)^2 : 0,3
a: \(=\dfrac{15}{4}:\dfrac{2-7}{16}-\dfrac{5}{9}\cdot\left(\dfrac{3}{5}+\dfrac{4}{5}\right)\)
\(=\dfrac{15}{4}\cdot\dfrac{16}{-5}-\dfrac{5}{9}\cdot\dfrac{7}{5}\)
\(=\dfrac{-240}{20}-\dfrac{7}{9}=-12-\dfrac{7}{9}=\dfrac{-115}{9}\)
c: \(=\dfrac{1}{5}-\dfrac{7}{2}-\dfrac{3}{2}+\dfrac{5}{4}\)
\(=\dfrac{4+25}{20}-5=\dfrac{29}{20}-\dfrac{100}{20}=\dfrac{-71}{20}\)
d: \(=\dfrac{12}{17}\left(1-\dfrac{1}{15}-\dfrac{4}{5}+1\right)=\dfrac{12}{17}\cdot\dfrac{17}{15}=\dfrac{12}{15}=\dfrac{4}{5}\)
e: \(=\dfrac{2}{15}\cdot\dfrac{9}{8}-\dfrac{7}{4}\cdot\dfrac{9}{8}+\dfrac{25}{36}\)
\(=\dfrac{9}{8}\left(\dfrac{2}{15}-\dfrac{7}{4}\right)+\dfrac{25}{36}\)
\(=\dfrac{9}{8}\cdot\dfrac{8-105}{60}+\dfrac{25}{36}\)
\(=\dfrac{9}{8}\cdot\dfrac{-97}{60}+\dfrac{25}{36}=\dfrac{-1619}{1440}\)
Bài 1: Thực hiện phép tính( bằng cahcs hợp lí nếu có thể)
\(a)\frac{7}{25}+\frac{4}{13}-\frac{5}{2}+\frac{18}{25}-1\frac{4}{13}\)
\(b)12-8.\left(\frac{3}{2}\right)^3\)
\(c)100\times\sqrt{0,04}+\sqrt{\frac{25}{16}}\)
\(d)\frac{1}{4}+\frac{3}{4}.\frac{5}{6}\)
\(e)3,75.7,2+2,8.3,75\)
\(f)\frac{1}{2}\sqrt{4}-\sqrt{25}\)
\(g)(\frac{1}{9})^{2005}.9^{2005}-96^2:24^2\)
\(h)\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{20}{15}+\frac{3}{7}\)
\(k)\left(-3,5\right).\left(-7,2\right)+\left(-3,15\right).12,4+4,8.\left(-3,15\right)\)
\(l)16\frac{2}{7}:\left(-\frac{2}{5}\right)-28\frac{2}{7}:\left(-\frac{2}{5}\right)\)
\(m)\left(-\frac{1}{2}\right)^3+\frac{1}{2}:5\)
\(n)1\frac{1}{23}+\frac{2}{21}-\frac{1}{23}+\frac{19}{21}+2013^0\)
\(h)\frac{-5}{9}.\left(\frac{3}{10}-\frac{2}{5}\right)\)
\(i)\frac{1}{2}\sqrt{64}-\sqrt{\frac{4}{25}+1^{2012}}\)
Giải Hộ Mk vs Mk đng cần gấp để nộp
HELP MEEEEEEEEEEEEEEEEEEEE
\(a)=\frac{7}{25}+\frac{4}{13}-\frac{5}{2}+\frac{18}{25}-\frac{17}{13}\)
\(=1-1-\frac{5}{2}\)
\(=-\frac{5}{2}\)
cái này bạn bấm máy tính là ra mà
giải giúp mk bài toán
a) x/3,15=0,15/7,2
b)x/6=24/25x
c)1/5:x=2/3:0,25
d)x-1/x+5=6/7
a) => x . 7,2 = 0,15 . 3,15
=> x . 7,2 =0,4725
=> x = 0,4725 : 7,2 =21/320
b) => x . 25x = 6.24
=> 25 . x2 =144
=> x2 = 144 : 25 =144/25
=> x= 12/5 hoặc -12/5 hoặc 12/-5
c) => 1/5:x =8/3
=> x = 1/5 :8/3 =3/40
d) => x-1 = 6,7 . ( x+5)
=> x-1 = 6,7x+33,5
=> x-6,7x = 33,5+1 =34,5
=> x ( 1-6,7) = 34,5
=> -5,7 x = 34,5
=> x = 34,5 : (-5,7) =-115/19
\(\frac{2^{10}.3^{31}+2^{40}.3^6}{2^{11}.3^{31}+2^{11}.3^6}\)
Tính:
a/\(\frac{3^{17}\cdot81^{11}}{27^{10}\cdot9^{15}}\)
b/\(\frac{9^2\cdot2^{11}}{16^2\cdot6^3}\)
c/\(\frac{2^{10}\cdot3^{31}+2^{40}\cdot3^6}{2^{11}\cdot3^{31}+2^{41}\cdot3^6}\)
\(\frac{3^{17}\cdot81^{11}}{27^{10}\cdot9^{15}}\)
\(=\frac{3^{17}\cdot\left(3^4\right)^{11}}{\left(3^3\right)^{10}\cdot\left(3^2\right)^{15}}\)
\(=\frac{3^{17}\cdot3^{44}}{3^{30}\cdot3^{30}}\)
\(=\frac{3^{61}}{3^{60}}\)
\(=3\)
\(\frac{9^2\cdot2^{11}}{16^2\cdot6^3}\)
\(=\frac{\left(3^2\right)^2\cdot2^{11}}{\left(2^4\right)^2\cdot\left(2\cdot3\right)^3}\)
\(=\frac{3^4\cdot2^{11}}{2^8\cdot2^3\cdot3^3}\)
\(=\frac{3^4\cdot2^{11}}{2^{11}\cdot3^3}\)
\(=\frac{3^4}{3^3}\)
\(=3\)
\(\frac{2^{10}\cdot3^{31}+2^{40}\cdot3^6}{2^{11}\cdot3^{31}+2^{41}\cdot3^6}\)
\(=\frac{2^{10}\cdot3^{31}+2^{40}\cdot3^6}{2\cdot\left(2^{10}\cdot3^{31}+2^{40}\cdot3^6\right)}\)
\(=\frac{1}{2}\)