a, 2.5x+1+10=60 c, (2x+1)2=25
b,(x-1)2=4 d, 2x+2x+3=144
a) (2x-1)^4=8^1
b) (x-1)^5= -32
c) 2^x +2^x+3=144
d) (2x-1)^6=(2x-1)^8
e) (x-7)^x+3 -(x-7)^x+1=0
tìm x\(\in\)Z biết
1.(-5)^2-(5x-3)=4
2.5x-15=-75-x
3.-2x-40=(5-x)-(-15+60)
4.3x^2=12
5.|2x-3|=7
6.19-(43-|x|)=45
Tìm x biết:
a) ( x-2)3 = 27
b) 2x + 2x+3= 144
c) ( 2x-3)2= 25
d) ( 2x-1)10= ( 2x-1) 100
c)(2x-3)^2 = 25
(2x-3)^2 = 5^2
=> 2x-3 = 5
2x = 8
x= 4
a) ( x-2)3 = 27
(x-2)^3 = 3^3
x-2 = 3
x= 5
b) 2x + 2x+3= 144
2^x + 2^x * 8 = 144
2^x (1+8) =144
2^x = 144:9
2^x = 16
2^x = 2^4
x=4
c) ( 2-3)2= 25
Câu c sao ko có x.
d) ( 2x-1)10= ( 2x-1) 100
(ko bt)
Tìm x biết:
a) ( x-2)3 = 27
b) 2x + 2x+3= 144
c) ( 2x-3)2= 25
d) ( 2x-1)10= ( 2x-1) 100
a. (x-2)3=27
<=> (x-2)3=33
=> x-2=3 =>x=5
c.(2x-3)2=25
<=> (2x-3)2=52
=>2x-3=5 => 2x=8 =>x=4
a) ( x-2)3 = 27
(x-2)3 = 33
x-2 = 3
x = 5
b) 2x + 2x+3= 144
2x ( 1 + 23 ) = 144
2x . 9 = 144
2x = 16
2x = 24
x = 4
c) ( 2x-3)2= 25
(2x-3)2 = 52
2x-3 = 5
2x = 8
x = 4
d) ( 2x-1)10= ( 2x-1) 100
Dễ thấy 2x - 1 = 0 vì 010 = 0100
Vậy x = 0,5
Nếu 2x - 1 \(\ne\)0
( 2x - 1 )10 : ( 2x - 1 )10 = ( 2x - 1 )100 : ( 2x - 1 )10
( 2x - 1 )90 = 1
Vậy 2x - 1 = 1 hoặc - 1.
Vậy x = 1 ; 0 ; 0,5.
Giai phương trình:
a)(x-5)(2x+3) = x^2 -25
b)2x/3 + 2x-1 /6 = x-1 /2
\(a,\left(x-5\right)\left(2x+3\right)=x^2-25\\ \Leftrightarrow a,\left(x-5\right)\left(2x+3\right)-\left(x-5\right)\left(x+5\right)=0\\ \Leftrightarrow\left(x-5\right)\left(2x+3-x+5\right)=0\\ \Leftrightarrow\left(x-5\right)\left(x+8\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=5\\x=-8\end{matrix}\right.\\ b,\dfrac{2x}{3}+\dfrac{2x-1}{6}=\dfrac{x-1}{2}\\ \Leftrightarrow\dfrac{4x}{6}+\dfrac{2x-1}{6}-\dfrac{3\left(x-1\right)}{6}=0\\ \Leftrightarrow4x+2x-1-3x+3=0\\ \Leftrightarrow3x+2=0\\ \Leftrightarrow x=-\dfrac{2}{3}\)
a)22+2x+3=144
b)(\(\sqrt{9}+\sqrt{4}\)).\(\sqrt{x}\)=10
c)(x+\(\dfrac{1}{2}\))2=\(\dfrac{4}{25}\)
a, x=2=35/2
x=log(35/2)
x=log(35)-log(20)
x=log(35)-1
b) \(\left(\sqrt{9}+\sqrt{4}\right).\sqrt{x}=10\)
\(\left(3+2\right).\sqrt{x}=10\)
\(5.\sqrt{x}=10\)
\(\sqrt{x}=2\)
\(x=\sqrt{2}\)
Câu 1 : x/3 = y/4; y/5 = z/7 và 2x + 3y - z = 186. Tổng x + y là :
A. 45 B. 60 C. 105 D.144
Áp dụng tc dtsbn:
\(\dfrac{x}{3}=\dfrac{y}{4};\dfrac{y}{5}=\dfrac{z}{7}\Leftrightarrow\dfrac{x}{15}=\dfrac{y}{20}=\dfrac{z}{28}=\dfrac{2x+3y-z}{30+60-28}=\dfrac{186}{62}=3\\ \Leftrightarrow\left\{{}\begin{matrix}x=45\\y=60\end{matrix}\right.\\ \Leftrightarrow x+y=105\left(C\right)\)
a)2x – 12.4 = 28
b)128-3(x +4)= 23
c) 20 + 8.(x + 3) = 52 .4
d) (12x -4 3 ).83= 4.84
e) 720: [41-(2x-5)]=23 .5
f) (2x- 4)(x – 3) = 0
g) (2x +1)3= 5.25
h) 2 x . 4 = 128
i) 5x-2 = 1
k)2x + 2x + 3= 144
giúp me được ko
Rút gọn các biểu thức sau:
a) (x-2)(x+3)+(1-x)(x+4)
b) (2x-3)^2-(2x-1)(2x+1)
c) (2x-8)(x+3)-(x-10)(2x+1)
d) (x+2)^3-(x-1)^3-4