√(√(81))-√(√(256))+√(12^2+5^2)
Những câu hỏi liên quan
a) 5√1,96 - 4√2,25 + 3√1,69
b) 1/3√49 + 3/4√324 - 2/3√400
c) 5/6√289 - 1/2√256 + 2/5√225
d) 15√16/25 + 12√9/16 - 18√16/81
a: =5*1,4-4*1,5+3*1,3
=7-6+3,9=4,9
b: =1/3*7+3/4*18-2/3*20
=7/3+54/4-40/3
=-11+54/4
=2,5
c: =5/6*17-1/2*16+2/5*15
=85/6-8+6
=85/6-2
=73/6
d: =15*4/5+12*3/4-18*4/9
=12+9-8
=12+1=13
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tìm x:
\(a,5^x.\left(5^2\right)^3=625\)
\(b,\left(\dfrac{12}{15}\right)^x=\left(\dfrac{5}{4}\right)^{-2}-\left(\dfrac{-3}{5}\right)^4\)
\(c,\left(\dfrac{-3}{4}\right)^{3x-1}=\dfrac{256}{81}\)
\(d,172x^2-7^9:98^3=2^{-3}\)
tìm x biết:
a) \(5^x.\left(5^3\right)^2=625\)
b)\(\left(\dfrac{12}{15}\right)^x=\left(\dfrac{5}{3}\right)^{-5}-\left(-\dfrac{3}{5}\right)^4\)
c)\(\left(-\dfrac{3}{4}\right)^{3x-1}=\dfrac{256}{81}\)
d)\(172x^2-7^9:98^3=2^{-3}\)
2 TÌM X BIẾT
a, (5x+1)^2 = 36/49
b, (12/25)^x =(5/3)^2 -(-3/5)^4
c, (-3/4)^ 3x-1 = 256/81
d, 172 .x ^2 -7^9 :98^3 =2^3
e,5^x .(5^3)^2 =625
f, (x-2/9)^3 =(2/3)^6
a)\(\left(5x+1\right)^2=\frac{36}{49}\\ \left(5x+1\right)^2=\left(\frac{6}{7}\right)^2\\ \Rightarrow\left[{}\begin{matrix}5x+1=\frac{6}{7}\\5x+1=\frac{-6}{7}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{-1}{35}\\x=\frac{-13}{35}\end{matrix}\right.\)
vậy...
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2.
a) \(\left(5x+1\right)^2=\frac{36}{49}\)
⇒ \(5x+1=\pm\frac{6}{7}\)
⇒ \(\left[{}\begin{matrix}5x+1=\frac{6}{7}\\5x+1=-\frac{6}{7}\end{matrix}\right.\) ⇒ \(\left[{}\begin{matrix}5x=\frac{6}{7}-1=-\frac{1}{7}\\5x=\left(-\frac{6}{7}\right)-1=-\frac{13}{7}\end{matrix}\right.\) ⇒ \(\left[{}\begin{matrix}x=\left(-\frac{1}{7}\right):5\\x=\left(-\frac{13}{7}\right):5\end{matrix}\right.\)
⇒ \(\left[{}\begin{matrix}x=-\frac{1}{35}\\x=-\frac{13}{35}\end{matrix}\right.\)
Vậy \(x\in\left\{-\frac{1}{35};-\frac{13}{35}\right\}.\)
Chúc bạn học tốt!
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Tìm x, biết
a, \(\left(\frac{12}{21}\right)^x=\left(\frac{3}{5}\right)^2-\left(-\frac{3}{5}\right)^4\)
b, \(\left(-\frac{3}{4}\right)^{3x-1}=\frac{256}{81}\)
Help me!!!
Tìm x
a, ( 12/25)x = (5/3)-2 - (-3/5)4
b, (-3/4)3x-1 = 256/81
c,172x22 - 79 : 983 = 2-3
giúp mình vs nhé 🙏🙏
256 ÷ 81 × 2 + 22 =50
Xem chi tiết
256 ÷ 81 × 2 + 22 =50
256 x 2: 81 + 22 = 50
512 : 81 = 50 - 22
512/81 = 28
Vô lí
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Xét vế trái:
256:81.2+22
= 256/81.2+22
= 512/81+22
= 2294/81
=> Vế trái < Vế phải
=> 2294/81< 50
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Tìm x: a) 8< 2^x < 2^9 * 2^-5
b) 27 < 81^3 / 3^x < 243
c) (2/5)^x > (5\2)^-3*(-2\5)^2
d) (-3/4)^3x-1 = 256/81
a: \(\Leftrightarrow2^3< 2^x< 2^4\)
=>3<x<4
mà x là số nguyên
nên \(x\in\varnothing\)
b: \(\Leftrightarrow3^3< 3^{12-x}< 3^5\)
=>12-x=4
hay x=8
c: \(\Leftrightarrow\left(\dfrac{2}{5}\right)^x>\left(\dfrac{2}{5}\right)^3\cdot\left(\dfrac{2}{5}\right)^2=\left(\dfrac{2}{5}\right)^5\)
=>x>5
d: \(\Leftrightarrow3x-1=-4\)
=>3x=-3
hay x=-1
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Tìm x: a) 8< 2^x < 2^9 * 2^-5
b) 27 < 81^3 / 3^x < 243
c) (2/5)^x > (5\2)^-3*(-2\5)^2
d) (-3/4)^3x-1 = 256/81
a: \(\Leftrightarrow2^3< 2^x< 2^4\)
=>3<x<4
mà x là số nguyên
nên \(x\in\varnothing\)
b: \(\Leftrightarrow3^3< 3^{12-x}< 3^5\)
=>12-x=4
hay x=8
c: \(\Leftrightarrow\left(\dfrac{2}{5}\right)^x>\left(\dfrac{2}{5}\right)^3\cdot\left(\dfrac{2}{5}\right)^2=\left(\dfrac{2}{5}\right)^5\)
=>x>5
d: \(\Leftrightarrow3x-1=-4\)
=>3x=-3
hay x=-1
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