Tìm x biết ( 7x-11)3 = (-3)2.15+208
Tìm x
a) \(\left(\frac{-5}{3}\right)< x< \frac{-24}{35}.\left(\frac{-5}{6}\right)\)
b) \(\left(7x-11\right)^3=\left(-3\right)^2.15+208\)
Tìm x
a. (2010-x).(x+2021)=0
b. (x-2)2+5.(x-2)=0
c. (6x-11)3.(-3)2.15=208
Cần gấp ạ
a) (2010 - x)(x + 2021) = 0
<=> \(\left[{}\begin{matrix}2010-x=0\\x+2021=0\end{matrix}\right.\)<=> \(\left[{}\begin{matrix}x=2010\\x=-2021\end{matrix}\right.\)
b) (x - 2)^2 + 5(x - 2) = 0
<=> x^2 - 4x + 4 + 5x - 10 = 0
<=> x^2 + x - 6 = 0
<=> x^2 - 2x + 3x - 6 = 0
<=> x(x - 2) + 3(x - 2) = 0
<=> (x + 3)(x - 2) = 0
<=> \(\left[{}\begin{matrix}x+3=0\\x-2=0\end{matrix}\right.\) <=> \(\left[{}\begin{matrix}x=-3\\x=2\end{matrix}\right.\)
Tìm x biết
(7x-11)^3 = (-3).15 + 208
Tìm x , biết:
a) (2x-15)5 = (2x-15)3
b) (7x-11)3 = (-3)2 . 15 + 208
Giúp mình nhanh nhé
a)
\(\left(2x-15\right)^5=\left(2x-15\right)^3\\ \Leftrightarrow\left(2x-15\right)^5-\left(2x-15\right)^3=0\\ \Leftrightarrow\left(2x-15\right)^3.\left[\left(2x-15\right)^2-1\right]=0\\ \Leftrightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15-1\right).\left(2d-15+1\right)=0\end{matrix}\right.\\\Leftrightarrow\left[{}\begin{matrix}2x-15=0\\2x-16=0\\2x-14=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=7\end{matrix}\right. \)
b) \(\left(7x-11\right)^3=\left(-3\right)^2.15+208\\ \Leftrightarrow\left(7x-11\right)^3=343=7^3\\ \Leftrightarrow7x-11=7\\ \Leftrightarrow x=\dfrac{18}{7}\)
Tìm số nguyên x biết :
\(\left(7x-11\right)^3=\left(-3\right)^2\cdot15+208\)
( 7x - 11 ) 3 = ( -3 )2 .15 + 208
( 7x - 11 ) 3 = 9 .15 + 208
( 7x - 11 ) 3 = 135 + 208
( 7x - 11 ) 3 = 343
( 7x - 11 ) 3 = 73
=> 7x - 11 = 7
=> 7x = 7 + 11 = 18
=> x = 18/7
\(\left(7x-11\right)^3=\left(-3\right)^2.15+208\)
\(\Leftrightarrow\)\(\left(7x-11\right)^3=9.15+208\)
\(\Leftrightarrow\)\(\left(7x-11\right)^3=135+208\)
\(\Leftrightarrow\)\(\left(7x-11\right)^3=343\)
\(\Leftrightarrow\)\(\left(7x-11\right)^3=7^3\)
\(\Leftrightarrow\)\(7x-11=7\)
\(\Leftrightarrow\)\(7x=18\)
\(\Leftrightarrow\)\(x=\frac{18}{7}\)
Vậy \(x=\frac{18}{7}\)
Chúc bạn học tốt ~
Tim x biet
(7x-11)^3=(-3)^2x15+208
Tìm x
x + 1/ 2 = 8/ -3
(-5/3)3 < x < -24/35 * -5/6
(7x-11)3 = (-3)2 *15 +208
1) \(x=\frac{8}{-3}-\frac{1}{2}=\frac{-19}{6}\)
2) \(\left(\frac{-5}{3}\right)^3=\frac{-125}{27}\)
\(\frac{-24}{35}.\frac{-5}{6}=\frac{4}{7}\)
Mà \(\frac{-125}{27}<0<\frac{4}{7}\)
=> \(x=0\)
3) \(\left(7.x-11\right)^3=343\)
=> \(\left(7.x-11\right)^3=7^3\)
=> \(7.x-11=7\)
=> \(x=\frac{7+11}{7}=\frac{18}{7}\)
(7x-11)^3=(-3)^2x15+208
\(\left(7x-11\right)^3=\left(-3\right)^2\cdot15+208\\ \Rightarrow\left(7x-11\right)^3=9\cdot15+208\\ \Rightarrow\left(7x-11\right)^3=135+208\\ \Rightarrow\left(7x-11\right)^3=343\\ \Rightarrow\left(7x-11\right)^3=7^3\\\Rightarrow7x-11=7\\ \Rightarrow7x=18\\ \Rightarrow x=\dfrac{18}{7} \)
Tìm x biết (7x-11)^3=3.(7x-11)^2