Tính nhanh
a) (20.24+12.24-48.22):82
b) (75.52+175.54):(20.125-625.75)
c) (6.64.82:(43-25.16)
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`(20.2^4+12.2^4-48.2^2):8^2`
`=(32.2^4-12.2^4):8^2`
`=[2^4.(32-12)]:8^2`
`=20.2^4:8^2`
`=20.16:64`
`=5`
Ta có: \(\left(20\cdot2^4+12\cdot2^4-48\cdot2^2\right):8^2\)
\(=\left(32\cdot2^4-12\cdot2^4\right):2^6\)
\(=20\cdot\dfrac{2^4}{2^6}\)
=5
a, (20.2^4+12.2^4-48.2^2):8^2
=(20.2^4+12.2^4-12.2^2.2^2):8^2
=(20.2^4+12.2^4-12.2^4):2^6
=2^4.(20+12-12):2^6
=2^4.20:2^6
=2^4.2^2.5:2^6
=5
b,
=5^4.(75+175):15625
=5^4.250:15625
=156250:15625
=10
c, Thì chắc bạn chép sai đề bài rồi,đề bài của mình thế này cơ:
16 x 64 x 82 : ( 43 x 25 x 16 )
=2^4.2^6.2^6:(2^6.2^5.2^4)
=2^18:2^5
=2^13
K MÌNH NHA
(75.54+175.54):(20.25.125-625.75)
=(4050+9450):(62500-46875)
=13500:15625
0,864 like nếu thích nha
(-5)^2-(5x-3)=43
25 - ( 5x - -3 ) = 43
5x -3 = 25 - 43
5x -3 = - 18
5x = - 18 + 3
5x = -15
x = -15 : 5
x = -3
Hok tốt
\(\left(-5\right)^2-\left(5x-3\right)=43\)
\(\Rightarrow25-5x+3=43\)
\(\Rightarrow28-5x=43\)
\(\Rightarrow5x=28-43=-15\)
\(\Rightarrow x=-3\)
Vậy x = -3
Lời giải:
ĐKXĐ: $x>0; x\neq 1$
\(P=\frac{1}{\sqrt{x}+1}+\frac{x}{\sqrt{x}(1-\sqrt{x})}=\frac{1}{\sqrt{x}+1}+\frac{\sqrt{x}}{1-\sqrt{x}}\)
\(=\frac{1-\sqrt{x}+\sqrt{x}(\sqrt{x}+1)}{(\sqrt{x}+1)(1-\sqrt{x})}=\frac{x+1}{1-x}\)
b. Khi $x=\frac{1}{\sqrt{2}}$ thì:
\(P=\frac{\frac{1}{\sqrt{2}}+1}{1-\frac{1}{\sqrt{2}}}=3+2\sqrt{2}\)
\(S=-\left(a-b-c\right)+\left(-c+b+a\right)-\left(a+b\right)\)
\(=-a+b+c-c+b+a-a-b\)
\(=-a+b\)
= \(b-a\)
Vì a > b \(\Rightarrow b-a< 0\) \(\Rightarrow|S|=\left(-1\right).\left(b-a\right)=-b+a=a-b\)
\(\Rightarrow|S|=a-b\)
Kb mình nha!
S = -(a-b-c)+(-c+b+a)-(a+b)
= - a+b+c-c+b+a-a+b
=(-a+a-a)+(b+b-b)+(c-c)
= -a+b+0
=b-a
Vì a>b nên |S| =a-b
a. \(\left(20.2^4+12.2^4-48.2^2\right):8^2\)
= \(\left[2^4.\left(20+12\right)-48.4\right]:64\)
= \(\left[16.32-192\right]:64\)
= \(\left[512-192\right]:64\)
= \(320:64\)
= \(5\)
b. \(\left(75.5^2+175.54\right):\left(20.125-625.75\right)\)
= \(\left(75.25+175.54\right):\left(20.125-625.75\right)\)
= \(\left(1875+9450\right):\left(2500-46875\right)\)
= \(11325:\left(-44375\right)\)
= \(\dfrac{-453}{1775}\)
c. \(\left[6.64.8^2:\left(4^3-2^5.16\right)\right]\)
= \(\left[6.64.64:\left(64-32.16\right)\right]\)
= \(\left[24576:\left(64-512\right)\right]\)
= \(\left[24576:\left(-448\right)\right]\)
= \(\dfrac{-387}{7}\)