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1)
a) \(x^3=-125\)
⇒ \(x^3=\left(-5\right)^3\)
⇒ \(x=-5\)
Vậy \(x=-5.\)
b) \(\left(x+5\right)^3=-64\)
⇒ \(\left(x+5\right)^3=\left(-4\right)^3\)
⇒ \(x+5=-4\)
⇒ \(x=\left(-4\right)-5\)
⇒ \(x=-9\)
Vậy \(x=-9.\)
Chúc bạn học tốt!
1) a) \(x^3=-125\)
\(\Rightarrow x=-5\)
b) \(\left(x+5\right)^3=-64\)
\(\rightarrow x+5=-4\)
\(\Rightarrow x=-9\)
2) \(M=\frac{8^{10}+4^{10}}{8^4+4^{12}}=\frac{4^{10}\left(2^{10}+1\right)}{4^4\left(16+4^8\right)}=\frac{1074790400}{16781312}=64,05\)
1) Tìm số nguyên x, biết :
a) 3x = 94/ 273
3x = 1/3
3x = 3-1
=> x = -1
b) 3x = 98 / 273 . 812
3x = 37.38
3x = 315
=> x = 15
c) 2x - 3 / 410 = 83
2x - 3 = 83.410
2x - 3 = 226
=> x - 3 = 26
=> x = 29
d) 22x - 3 / 410 = 83 . 165
22x - 3 / 410 = 269
22x - 3 = 269 . 410
22x - 3 = 289
=> 2x - 3 = 89
2x = 91
x = 91/2
e) 35 / 3x = 310
3x = 35 : 310
3x = 3-5
=> x = -5
B1:
a)x=-3/5*9/25 =>x=-27/125
b)x=(4/7)6:(4/7)4 =>x=(4/7)2=16/49
c)(x/4)2=4:(x/2)
(x/4)2=8/x
x2/16=8/x2
x3=128
x=5,039
B2
M=23.10+22.10/23.4+22.11
=230+220/212+222
=230+28+222
=28(222+1+214)
=2
nhầm, sorry:
a) 10x : 5y = 20y
=> 10x = 20y . 5y
=> 10x = 100y
=> 10x = (102)y
=> x = 2y
\(A=\frac{\left(2^3\right)^{10}+\left(2^2\right)^{10}}{\left(2^3\right)^4+\left(2^2\right)^4}=\frac{2^{30}+2^{20}}{2^{12}+2^8}=\frac{2^{20}\left(2^{10}+1\right)}{2^8\left(2^4+1\right)}=\frac{2^{12}\left(2^{10}+1\right)}{2^4+1}\)
Bài 1:
a)
\(\dfrac{4^2\cdot25^2+32\cdot125}{2^3\cdot5^2}\\ =\dfrac{\left(2^2\right)^2\cdot\left(5^2\right)^2+2^5\cdot5^3}{2^3\cdot5^2}\\ =\dfrac{2^{2\cdot2}\cdot5^{2\cdot2}+2^5\cdot5^3}{2^3\cdot5^2}\\ =\dfrac{2^4\cdot5^4+2^5\cdot5^3}{2^3\cdot5^2}\\ =\dfrac{2^4\cdot5^4}{2^3\cdot5^2}+\dfrac{2^5\cdot5^3}{2^3\cdot5^2}\\ =2\cdot5^2+2^2\cdot5\\ =2\cdot25+4\cdot5\\ =50+20\\ =70\)
c)
\(\dfrac{\left(1-\dfrac{4}{9}-2\right)\cdot16}{\left(2-3\right)^{-2}}+12\\ =\dfrac{\left(\dfrac{9}{9}-\dfrac{4}{9}-\dfrac{18}{9}\right)\cdot16}{\left(-1\right)^{-2}}+12\\ =\dfrac{\dfrac{-13}{9}\cdot16}{\dfrac{1}{\left(-1\right)^2}}+12\\ =\dfrac{\dfrac{-208}{9}}{1}+12\\ =\dfrac{-208}{9}+12\\ =\dfrac{-208}{9}+\dfrac{108}{9}\\ =\dfrac{100}{9}\)
Bài 2:
a)
\(\left(x+2\right)^2=36\\ \Rightarrow\left[{}\begin{matrix}x+2=6\\x+2=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=4\\x=-8\end{matrix}\right.\)
b)
\(\left(1,78^{2x-2}-1,78^x\right):1,78^x=0\\ \Leftrightarrow\dfrac{1,78^{2x-2}}{1,78^x}-\dfrac{1,78^x}{1,78^x}=0\\ \Leftrightarrow\dfrac{1,78^{2x-2}}{1,78^x}-1=0\\ \Leftrightarrow \dfrac{1,78^{2x-2}}{1,78^x}=1\\ \Leftrightarrow1,78^{2x-2}=1,78^x\\ \Leftrightarrow2x-2=x\\ \Leftrightarrow2x-x=2\\ \Leftrightarrow x=2\)
d) \(5^{\left(x-2\right)\left(x+3\right)}=1\)
\(\Rightarrow5^{\left(x-2\right)\left(x+3\right)}=5^0\)
\(\Leftrightarrow\left(x-2\right)\left(x+3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x+3=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\)
Vậy \(x_1=-3;x_2=2\)
a)=8
b)1/27
c)-1/16
d)=8
e)=216
f)=7
g)=1 (hay sao ý ) phần g ko chắc
a)x^3 = -125 b)(x+5)^3 = -64
=> x^3 = (-25)^3 => (x+5)^3 = (-4)^3
=> x = -25 => x+5 = -4
vay x = -25 => x = -4-5
=>x = -9
bai 2 mk chịu sr nha
bai a cua chinh sai bai b dung
bài 2
M=\(\frac{8^{10}+4^{10}}{8^4+4^{10}}\)=\(8^6\)
minh nghi the