Tìm x, biết:
a) 4 1 2 − x = − 3 2 3
b) x − 2 2 3 = 3 1 3
Bài 4. Tìm số nguyên x , biết:
a) |x - 2|= 0 b) |x + 3|= 1 c) -3 |4 - x|= -9 d) |2x + 1|= -2
Bài 5. Tìm số nguyên x, biết:
a) (x + 3)mũ 2 = 36 b) (x + 5)mũ 2 =100 c) (2x - 4)mũ 2 = 0 d) (x - 1)mũ 3 = 27
bài 2:tìm x, biết:
a. x + 1^3 = 2^5 - ( -1^3 )
b. 3^7 - x = 1^4 - ( -3^5 )
a) \(x+1^3=2^5-\left(-1^3\right)\)
\(\Rightarrow x+1=33\)
=> x = 32
b) \(3^7-x=1^4-\left(-3^5\right)\)
\(\Rightarrow2187-x=1+243=244\)
=> x = 1943
a) \(\Leftrightarrow x+1=32+1\)
\(\Leftrightarrow x=32\)
Vậy x = 32
b) \(\Leftrightarrow2187-x=1+243\)
\(\Leftrightarrow2187-x=244\)
\(\Leftrightarrow x=1943\)
Vậy x = 1943
a) \(x+1^3=2^5-\left(-1^3\right)\)
\(x+1=32-\left(-1\right)\)
\(x+1=33\)
\(x=33-1\)
\(x=32\)
b) \(3^7-x=1^4-\left(-3^5\right)\)
\(2187-x=1-\left(-243\right)\)
\(2187-x=244\)
\(x=2187-244\)
\(x=1943\)
tìm x biết:
a. 2.3^x - 405=3^(x-1)
b. (3/4)^x = 2^8/3^4
c. (5x+1)^2=36/49
d. (x+1)^(x+10)= (x+1)^(x+4)
Tìm x, biết:
a) \(\left(\dfrac{3}{4}.x+2\dfrac{1}{2}\right).\dfrac{-2}{3}=\dfrac{1}{8}\)
b) \(\dfrac{1}{3}.x-0,5.x=0,75\)
a: \(\left(\dfrac{3}{4}x+2\dfrac{1}{2}\right)\cdot\dfrac{-2}{3}=\dfrac{1}{8}\)
=>\(\left(\dfrac{3}{4}x+\dfrac{5}{2}\right)=\dfrac{1}{8}:\dfrac{-2}{3}=\dfrac{-3}{16}\)
=>\(\dfrac{3}{4}x=-\dfrac{3}{16}-\dfrac{5}{2}=-\dfrac{3}{16}-\dfrac{40}{16}=-\dfrac{43}{16}\)
=>\(x=-\dfrac{43}{16}:\dfrac{3}{4}=\dfrac{-43}{16}\cdot\dfrac{4}{3}=\dfrac{-43}{12}\)
b: \(\dfrac{1}{3}\cdot x-0,5x=0,75\)
=>\(x\left(\dfrac{1}{3}-\dfrac{1}{2}\right)=0,75\)
=>\(x\cdot\dfrac{-1}{6}=0,75\)
=>\(x=-0,75\cdot6=-4,5\)
Bài 4. Tìm x, biết:
a) (2x + 1)^2 - 4(x + 2)^2 = 9
b) (x + 3)^2 - (x - 4)( x + 8) = 1
c) 3(x + 2)^2 + (2x - 1)^2 - 7(x + 3)(x - 3) = 36
\(a,\left(2x+1\right)^2-4\left(x+2\right)^2=9\\ \Leftrightarrow4x^2+4x+1-4\left(x^2+4x+4\right)-9=0\\ \Leftrightarrow4x^2-4x^2+4x-16x+1-16-9=0\\ \Leftrightarrow-12x=24\\ \Leftrightarrow x=\dfrac{24}{-12}=-2\\ b,\left(x+3\right)^2-\left(x-4\right)\left(x+8\right)=1\\ \Leftrightarrow x^2+6x+9-\left(x^2+4x-32\right)=1\\ \Leftrightarrow x^2-x^2+6x-4x=1-9-32\\ \Leftrightarrow2x=-40\\ \Leftrightarrow x=-20\\ c,3\left(x+2\right)^2+\left(2x-1\right)^2-7\left(x+3\right)\left(x-3\right)=36\\ \Leftrightarrow3\left(x^2+4x+4\right)+\left(4x^2-4x+1\right)-7\left(x^2-9\right)=36\\ \Leftrightarrow3x^2+12x+12+4x^2-4x+1-7x^2+63=36\\ \Leftrightarrow3x^2+4x^2-7x^2+12x-4x=36-12-1-63\\ \Leftrightarrow8x=-40\\ \Leftrightarrow x=\dfrac{-40}{8}=-5\)
1. Tìm số nguyên x, y biết:
a) \(^{3^{4-x}}=27\)
b) \(^{3^{-1}}.^{4^x}+3.^{4^x}=\dfrac{5}{3}.^{2^7}\)
Tìm x, biết:
a, \(\left(2\dfrac{3}{4}-1\dfrac{4}{5}\right)x=1\)
b, \(x^2-9\) \(3-5x=0\)
c, \(\left|3x-1\right|+2\dfrac{3}{4}=3\dfrac{1}{16}\)
a) \(\left(2\dfrac{3}{4}-1\dfrac{4}{5}\right)\cdot x=1\)
\(\left(\dfrac{11}{4}-\dfrac{9}{5}\right)\cdot x=1\)
\(\dfrac{19}{20}x=1\)
\(x=\dfrac{20}{19}\)
Vậy \(x=\dfrac{20}{19}\)
b) \(\left(x^2-9\right)\left(3-5x\right)=0\)
TH1:
\(x^2-9=0\)
\(x^2=9\)
\(x^2=3^2=\left(-3\right)^2\)
=>\(x\in\left\{3;-3\right\}\)
TH2:
\(3-5x=0\)
\(5x=3\)
\(x=\dfrac{3}{5}\)
Vậy \(x\in\left\{3;-3;\dfrac{3}{5}\right\}\)
tìm x biết:
a/2*(x^4+3)-(-9)=17
b/5^2*x+1-3*4^2=-47
2(x4+3)-(9)=17
⇒2x4+6+9=17
⇒2x4+15=17
⇒ 2x4=2
⇒ x4=1
⇒ x=\(\pm1\)
b) 5x2.x+1-3.42=-47
⇒5x3+1-48=-47
⇒5x3-47=-47
⇒5x3=0
⇒x3=0
⇒x=0
a) \(2\left(x^4+3\right)-\left(-9\right)=17\)
\(2x^4+6+9=17\)
\(2x^4=2\)
\(x^4=1\)
⇒ \(x=1\)
a) 2*(x⁴+3)-(-9)=17
=>2x⁴+2*3+9=17
=>2x⁴+6=17-9=8
=>2x⁴=8-6=2
=>x⁴=2/2=1
=>x=1
Tìm x biết:
a) x-\(\dfrac{2}{3}\)=\(\dfrac{3}{8}\) b) x-\(\dfrac{3}{4}\)=\(\dfrac{13}{10}\):\(\dfrac{26}{5}\) c) \(\dfrac{3}{2}\)-\(\left(x+\dfrac{1}{2}\right)\)=\(\dfrac{4}{5}\) d) |x-2|-1=0
a) \(x-\dfrac{2}{3}=\dfrac{3}{8}\Rightarrow x=\dfrac{3}{8}+\dfrac{2}{3}=\dfrac{25}{24}\)
b) \(x-\dfrac{3}{4}=\dfrac{13}{10}:\dfrac{26}{5}\Rightarrow x-\dfrac{3}{4}=\dfrac{1}{4}\Rightarrow x=\dfrac{1}{4}+\dfrac{3}{4}=1\)
c) \(\dfrac{3}{2}-\left(x+\dfrac{1}{2}\right)=\dfrac{4}{5}\Rightarrow x+\dfrac{1}{2}=\dfrac{3}{2}-\dfrac{4}{5}=\dfrac{7}{10}\)
\(\Rightarrow x=\dfrac{7}{10}-\dfrac{1}{2}=\dfrac{1}{5}\)
d) \(\left|x-2\right|-1=0\Rightarrow\left|x-2\right|=1\)
\(\Rightarrow\left[{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=3\\x=1\end{matrix}\right.\)
a: Ta có: \(x-\dfrac{2}{3}=\dfrac{3}{8}\)
\(\Leftrightarrow x=\dfrac{3}{8}+\dfrac{2}{3}=\dfrac{9}{24}+\dfrac{16}{24}=\dfrac{25}{24}\)
b: Ta có: \(x-\dfrac{3}{4}=\dfrac{13}{10}:\dfrac{26}{5}\)
\(\Leftrightarrow x-\dfrac{3}{4}=\dfrac{13}{10}\cdot\dfrac{5}{26}=\dfrac{1}{4}\)
hay x=1
Tìm x, biết:
a) \(\left(3\dfrac{1}{2}+2x\right).2\dfrac{2}{3}=5\dfrac{1}{3}\)
b) \(\left(2x+3\right)=5\)
c) \(\dfrac{x-2}{4}=\dfrac{5+x}{3}\)
a: \(\Leftrightarrow2x+\dfrac{7}{2}=\dfrac{16}{3}:\dfrac{8}{3}=2\)
=>2x=-3/2
hay x=-3/4
b: 2x+3=5
=>2x=2
hay x=1
c: =>3(x-2)=4(5+x)
=>4x+20=3x-6
=>x=-26
a) => (7/2 + 2x) . 8/3 = 16/3
=> 7/2 + 2x = 16/3 : 8/3
=> 7/2 + 2x = 2
=> 2x = 2 - 7/2
=> 2x = -1.5
=> x = -1.5 : 2
=> x = -0.1