2x+2x-3-2x+5=73
tìm x
Bài 8. Tìm x ϵ N biết:
a) x3=27
b) (2x-1)3=8
c) (x-2)2=16
d) (2x – 3)2=9
e) 2x+5=34:32
f) (3x-24).73=2.74
Bài 8. Tìm x ϵ N biết:
a) x3=27
b) (2x-1)3=8
c) (x-2)2=16
d) (2x – 3)2=9
e) 2x+5=34:32
f) (3x-24).73=2.74
a 575 - (2x +70)=445
b 575-2 (x+70)=445
c x5=32
d (3x-1)3=8
e (x-2)3=27
f (2x-3)2=9
g 2x+5 =34:32
h (4x -52).73=74
a: \(575-\left(2x+70\right)=445\)
=>\(2x+70=575-445=130\)
=>\(2x=130-70=60\)
=>x=60/2=30
b: \(575-2\left(x+70\right)=445\)
=>\(2\left(x+70\right)=575-445=130\)
=>x+70=130/2=65
=>x=65-70=-5
c: \(x^5=32\)
=>\(x^5=2^5\)
=>x=2
d: \(\left(3x-1\right)^3=8\)
=>\(\left(3x-1\right)^3=2^3\)
=>3x-1=2
=>3x=3
=>\(x=\dfrac{3}{3}=1\)
e: \(\left(x-2\right)^3=27\)
=>\(\left(x-2\right)^3=3^3\)
=>x-2=3
=>x=5
f: \(\left(2x-3\right)^2=9\)
=>\(\left[{}\begin{matrix}2x-3=3\\2x-3=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=6\\2x=0\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}x=3\\x=0\end{matrix}\right.\)
g: \(2x+5=3^4:3^2\)
=>\(2x+5=3^2\)
=>2x+5=9
=>2x=9-5=4
=>x=4/2=2
h: \(\left(4x-5^2\right)\cdot7^3=7^4\)
=>\(4x-25=\dfrac{7^4}{7^3}=7\)
=>4x=25+7=32
=>\(x=\dfrac{32}{4}=8\)
Tìm số tự nhiên x biết:
7⁵ : 73 - x = 23
( 2x -7 ).5⁸=5¹⁰
\(7^5:7^3-x=23\)
\(7^2-x=23\)
\(49-x=23\)
\(x=49-23\)
\(x=26\)
\(\left(2x-7\right).5^8=5^{10}\)
\(\left(2x-7\right)=5^{10}:5^8\)
\(2x-7=5^{10-8}\)
\(2x-7=5^2\)
\(2x-7=25\)
\(2x=32\)
\(x=32:2\)
\(x=16\)
* Mình nghĩ câu a sửa đề như vậy sẽ đúng hơn!
tìm x biết
(2x+5).|-7| = 73
\(\left(2x+5\right).\left|-7\right|=73\)
\(\left(2x+5\right).7=73\)
\(\left(2x+5\right)=\frac{73}{7}\)
\(2x=\frac{73}{7}-5=\frac{38}{7}\)
\(x=\frac{38}{7}:2=\frac{19}{7}\)
(2x+5).7=73
tìm x
(2x+5).7=73
<=>2x.7+5.7=73
<=>14x+35=73
<=>14x=73-35
<=>14x=38
<=>x=38:14
=>x= 17/7
Tìm x
( 2x + 5 ) . | -7 | = 73
(2x+5) . l-7l = 73
=(2x+5) . 7 =73
=(2x+5) =\(\frac{73}{7}\)
=2x =\(\frac{73}{7}\) - 5
=2x =\(\frac{38}{7}\)
=x =\(\frac{38}{7}\) :2
=x =\(\frac{19}{7}\)
(2x+5).|-7|=73
=> (2x+5).7=73
=> 2x+5=73:7
=> 2x+5=\(\frac{73}{7}\)
=>2x=\(\frac{73}{7}\)-5
=>2x=\(\frac{38}{7}\)
=>x=\(\frac{38}{7}\):2
=>x=\(\frac{19}{7}\)
vậy.....
giúp tôi với : tìm x : ( 2x+5 ) .7 = 73
Tìm x thuộc Z:
14) 24 ( 2x + 11)2 = 42
15) 73x - 2 - 3. 73 = 73. 4
15: \(\Leftrightarrow3x-2=1\)
hay x=1