\(\Leftrightarrow2^x=\dfrac{2^{30}\cdot5^7+2^{13}\cdot5^{27}}{2^{27}\cdot5^7+2^{10}\cdot5^{27}}\)
\(\Leftrightarrow2^x=\dfrac{2^{13}\cdot5^7\left(2^{17}+5^{20}\right)}{2^{10}\cdot5^7\left(2^{17}+5^{20}\right)}=2^3\)
=>x=3
\(\dfrac{4}{9}.19\dfrac{1}{3}+\dfrac{-4}{9}.39\dfrac{1}{3}+\dfrac{-3^2}{5}:\left(-0,2\right)\)
\(\dfrac{\left(-5^3\right)^2}{27}.\dfrac{3}{23}.\dfrac{6^2}{-5^6}\)
\(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
\(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}:33\dfrac{1}{3}\)
\(\dfrac{3}{4}-\left(x+\dfrac{1}{2}\right)=\dfrac{4}{5}\)
x:(-2,14)=(-3,12):1,2
Tính:
a) \(\dfrac{3}{7}+\left(-\dfrac{5}{2}\right)+\left(-\dfrac{3}{5}\right)\)
b) \(\dfrac{-8}{18}-\dfrac{15}{27}\)
c) \(3,5-\left(-\dfrac{2}{7}\right)\)
1) A = \(\left(-\dfrac{25}{27}-\dfrac{31}{42}\right)-\left(\dfrac{-7}{27}-\dfrac{3}{42}\right)\)
2) B = \(\dfrac{10\dfrac{3}{10}-\left(9,5-0,25\times18\right)\div0,5}{1\dfrac{1}{5}-1\dfrac{1}{2}}\)
3) C = \(\dfrac{3}{49}\times\dfrac{19}{2}-\dfrac{3}{49}\times\dfrac{5}{2}-\left(\dfrac{1}{20}-\dfrac{1}{4}\right)^2\times\left(\dfrac{-1}{2}-\dfrac{193}{14}\right)\)
Tìm x biết : a) x+3/22=-27/121.11/9 b) (3và2/20-2và1/20)x+2/7=3/5 c) |3/2x-5|-1/2=-1/4
Bài 1:Tính
1) (1/2)^3 (3/2)^2
2) (2/3)^3 (3/2)^5
3) (5/4)^5 (4/5)^7
4) (-5/6)^6 (6/5)^8
5)(-4/3)^3 (9/16)^5
6) (1/3)^4 (-9/2)^6
7)(-4/9)^3 (-27/20)^4
8) (0,2)^4 . 5^6
9) (-4/3)^3 (9/16)^5
10) (-0,2)^3 .(-5)^5
11) (-4)^4 .(0,25)^6
12) $^2 . (0,2)^3
13) (0,5)^2 . 2^4
14) (-0,5)^3 .2^6
15) (-0,5)^5 .(-2)^10
16) (0,125)^2 .8^4
17) (0,125)^5 . (-8)^4
18) (-0,125)^7 . 8^10
19) (-0,1)^4 . 10^7
20) (0,1)^5 . (-10)^10
Giúp mình với ạ,mình cảm ơn ạ
1)Tính giá trị biểu thức:
\(\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{7}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
2)Tìm x biết:
a) \(42+\dfrac{3}{7}.\left|3x-1\right|=12\)
b) \(\left|2x-1\right|=\left|x+2\right|\)
c) \(2.3^x.3^2=18\) với \(x\in N\)
Tính nhanh :
\(A=\left(-\dfrac{5}{7}+\dfrac{8}{5}\right):\dfrac{91}{8}+\left(-\dfrac{2}{7}-\dfrac{3}{5}\right):\dfrac{91}{8}\)
\(B=\dfrac{13}{15}:\left(\dfrac{4}{5}-\dfrac{3}{7}\right)+\dfrac{13}{15}:\left(\dfrac{2}{5}-\dfrac{1}{9}\right)\)
(Gíup mình với )
Tính
1. 6/5 - 1/4 + 4/5 - 3/4
2. 7/9 - 5/12 + 2/9 - 7/12
3. -4/15 + 5/13 - 11/15 + 8/13
4. 9/15 - 7/13 +6/15 - 6/13
5. 12/5 - 3/7 + 3/5 - 4/7
6. 6/5 - 1/4 + 4/5 - 3/4 + 1/2
7. 13/7 - 8/6 + 8/7 - 4/6 - 1/3
rút gọn biểu thức :
A= 937.1-4.5)-(-4.5+37.1)-100
B= 2^15 *9^4/6^6*8^3
C= tử số : (13và 1/4 -2vaf 5/27-10va 5/6)*230 và 1/25+46 và 3/4 +46 và 3/4
mẫu số : 1 và 3/7+10/3)/ (12 và 1/3 -14 và 2/7 )
D= (0.8 *7+0.8^2)*(1.25*7-4/5*1.25)+31.64
