Tìm số nguyên x biết :
\(\left(7x-11\right)^3=\left(-3\right)^2\cdot15+208\)
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
\(\left(6x-11\right)^3\)=\(\left(-3^{ }\right)^2\) . 15 +208
(6x - 11)3 = (-3)2 . 15 + 208
(6x - 11)3 = 9 . 15 + 208
(6x - 11)3 = 135 + 208
(6x - 11)3 = 343
(6x - 11)3 = 73 (cùng số mũ)
⇒6x - 11 = 7
6x = 7 + 11
6x = 18
x =3
Tìm x biết : \(\left(\frac{2}{11\cdot13}+\frac{2}{13\cdot15}+....+\frac{2}{19\cdot21}\right)\cdot462-\left(2,04:\left(x+1,05\right)\right):0,12=19\)
Tìm \(x\)
\(\left(7x-11\right)^3=2^5.5^2+200\)
\(\left(7x-11\right)^3=2^5.5^2+200\)
\(\Leftrightarrow\left(7x-11\right)^3=1000\)
\(\Leftrightarrow7x-11=10\)
\(\Leftrightarrow7x=21\)
\(\Leftrightarrow x=3\)
\(\left(7x-11\right)^3=2^5.5^2+200\)
\(\Rightarrow\left(7x-11\right)^3=32.25+200\)
\(\Rightarrow\left(7x-11\right)^3=800+200\)
\(\Rightarrow\left(7x-11\right)^3=1000=10^3\)
\(\Rightarrow7x-11=10\)
\(\Rightarrow7x=21\)
\(\Rightarrow x=3\)
\(\left(7x-11\right)^3=2^5.5^2+200\)
\(\Rightarrow\left(7x-11\right)^3=32.25+200\)
\(\Rightarrow\left(7x-11\right)^3=800+200\)
\(\Rightarrow\left(7x-11\right)^3=1000=10^3\)
\(\Rightarrow7x-11=10\)
\(\Rightarrow7x=21\)
\(\Rightarrow x=3\)
Tìm x, biết:
a. \(\left|3x-1\right|+\left|x-2\right|-\left|x+3\right|=10\)
b. \(\left|x.\left(x^2+3\right)\right|-7x=0\)
Đối với các dạng toán như thế này thì phải xét khoảng
Bạn giải giúp mình vời. Mình sẽ k cho bạn
Bài 5: Tìm x;y;z biết: |3x-5|+\(\left(2y+5\right)^{208}\)\(\left(4z-3\right)^{20}\)≤0
Sửa đề \(\left|3x-5\right|+\left(2y+5\right)^{208}+\left(4x-3\right)^{20}\le0\)
Mà \(\left|3x-5\right|\ge0\);\(\left(2y+5\right)^{208}\ge0;\left(4x-3\right)^{20}\ge0\)
Do đó \(\left|3x-5\right|+\left(2y+5\right)^{208}+\left(4z-3\right)^{20}=0\)
\(\Rightarrow\left\{{}\begin{matrix}3x-5=0\\2y+5=0\\4z-3=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=\dfrac{5}{3}\\y=-\dfrac{5}{2}\\z=\dfrac{3}{4}\end{matrix}\right.\)
Tìm số nguyên x , biết :
a) \(3\frac{2}{3}.\left(\frac{1}{5}-\frac{1}{2}\right)< x< \frac{3}{11}.\left(\frac{1}{5}+\frac{2}{3}-\frac{1}{2}\right)\)
b) \(4,85-\left(3\frac{1}{8}+1,105\right)< x< 91-\left(6,85-2\frac{3}{4}\right)\)
tìm x biết\(\left(7x-11\right)^3=2^5.5^2+200\)
(7x-11)3 = 25.52+ 23.52
(7x-11)3 = 23.52( 22+1)
(7x-11)3 = 23.53=(2.5)3
7x-11=10
x=3
ban anhduc1501 hinh nhu lam chua dung to nghi vay
(7x - 11)3 = 25 . 52 + 200
(7x - 11)3 = 32 . 25 + 200
(7x - 11)3 = 800 + 200
(7x - 11)3 = 1000
(7x - 11)3 = 103
7x - 11 = 10
7x = 21
x = 3
Rút gọn phân thức sau ( phân thức đều có nghĩa )
\(N=\dfrac{\left(x+2\right)\left(x+3\right)\left(x+4\right)\left(x+5\right)+1}{x^2+7x+11}\)
\(N=\dfrac{\left(x+2\right)\left(x+3\right)\left(x+4\right)\left(x+5\right)+1}{x^2+7x+11}\)
\(=\dfrac{\left[\left(x+2\right)\left(x+5\right)\right]\cdot\left[\left(x+3\right)\left(x+4\right)\right]+1}{x^2+7x+11}\)
\(=\dfrac{\left(x^2+7x+10\right)\left(x^2+7x+12\right)+1}{x^2+7x+11}\)
Đặt \(x^2+7x+11=y\), thay vào \(N\) ta được:
\(N=\dfrac{\left(y-1\right)\left(y+1\right)+1}{y}\)
\(=\dfrac{y^2-1+1}{y}\)
\(=\dfrac{y^2}{y}\)
\(=y\)
\(=x^2+7x+11\)
Vậy \(N=x^2+7x+11\).
\(\text{#}Toru\)