$x=\root(3)(22\sqrt(2+)25-\root(3)(22\sqrt(2))- 25)$
\(\sqrt[3]{22\sqrt{2}+25}-\sqrt[3]{22\sqrt{2}-25}\)
Đặt \(A=\sqrt[3]{22\sqrt{2}+25}-\sqrt[3]{22\sqrt{2}-25}\)
\(\Rightarrow A^3=22\sqrt{2}+25-\left(22\sqrt{2}-25\right)-3\sqrt[3]{\left(22\sqrt{2}+25\right)\left(22\sqrt{2}-25\right)}.\)
\(\left(\sqrt[3]{22\sqrt{2}+25}-\sqrt[3]{22\sqrt{2}-25}\right)\)
\(=50-3\sqrt[3]{\left(22\sqrt{2}\right)^2-25^2}.A\)
\(\Rightarrow A^3=50-3A\sqrt[3]{343}\Leftrightarrow A^3=50-21A\)
\(\Leftrightarrow A^3+21A-50=0\Leftrightarrow A^3-4A+25A-50=0\)
\(\Leftrightarrow A\left(A^2-4\right)+25\left(A-2\right)=0\Leftrightarrow\left(A-2\right)\left(A+2\right)A+25\left(A-2\right)=0\)
\(\Leftrightarrow\left(A-2\right)\left(A^2+2A+25\right)=0\)
Vì \(A^2+2A+25=\left(A+1\right)^2+24>0,\forall A\Rightarrow A-2=0\Leftrightarrow A=2\)
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) \(\left(\sqrt{9}+\sqrt{4}\right).\sqrt{x}=10\)
\(\left(3+2\right).\sqrt{x}=10\)
\(5.\sqrt{x}=10\)
\(\sqrt{x}=2\)
\(x=\sqrt{2}\)
`(\root[3]{26+15\sqrt{3}}-\sqrt{3})/(\sqrt{6-2\sqrt{5}-\sqrt{5})`
\(=\dfrac{2+\sqrt{3}-\sqrt{3}}{\sqrt{5}-1-\sqrt{5}}=-2\)
Giải phường trình:
d)\(\dfrac{25}{\sqrt{x-2}}+\dfrac{4}{\sqrt{y-3}}+\dfrac{16}{\sqrt{z-4}}=22-\sqrt{x-2}-\sqrt{y-3}-\sqrt{z-4}\)
root(5x + 2, 3) = 3 5sqrt(4x - 16) - 7/3 * sqrt(9x - 36) = 36 - 3sqrt(x - 4)
b:
ĐKXĐ: x>=4
\(5\sqrt{4x-16}-\dfrac{7}{3}\cdot\sqrt{9x-36}=36-3\sqrt{x-4}\)
=>\(5\cdot2\cdot\sqrt{x-4}-\dfrac{7}{3}\cdot3\cdot\sqrt{x-4}+3\sqrt{x-4}=36\)
=>\(6\sqrt{x-4}=36\)
=>\(\sqrt{x-4}=6\)
=>x-4=36
=>x=40
Giải phương trình
a) \(\sqrt{x-2\sqrt{x-1}}-\sqrt{x-1}=1\)
b)\(\sqrt{x^4++2x^2+1}=\sqrt{x^2+10x+25}-10x+22\)
a) Ta có: \(\sqrt{x-2\sqrt{x-1}}-\sqrt{x-1}=1\)
\(\Leftrightarrow\left|\sqrt{x-1}-1\right|=\sqrt{x-1}+1\)
\(\Leftrightarrow\sqrt{x-1}=\sqrt{x-1}+1+1\)(Vô lý)
Vậy: \(S=\varnothing\)
b) Ta có: \(\sqrt{x^4+2x^2+1}=\sqrt{x^2+10x+25}-10x+22\)
\(\Leftrightarrow x^2+1=\left|x+5\right|-10x+22\)
\(\Leftrightarrow\left|x+5\right|=x^2+1+10x-22=x^2+10x-21\)
\(\Leftrightarrow\left[{}\begin{matrix}x+5=x^2+10x-21\left(x\ge-5\right)\\-x-5=x^2+10x-21\left(x< -5\right)\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x^2+10x-21-x-5=0\\x^2+10x-21+x+5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x^2+9x-26=0\\x^2+11x-16=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-9+\sqrt{185}}{2}\\x=\dfrac{-11-\sqrt{185}}{2}\end{matrix}\right.\)
tính E= \(\sqrt[3]{99+70\sqrt{2}}+\sqrt[3]{25-22\sqrt{2}}.\)
giúp mình với mình cần gấp
Với `p;q;r;s\inRR : {(p+q+r+s=0),(p<q<r<s):}` chứng minh rằng: `p<1/2 \root[3]{(\sqrt(24(pq+pr+ps+qr+qs+rs)^3+81(pqr+qrs+rsp+spq)^2)+9(pqr+qrs+rsp+spq))/(9)}-(pq+pr+ps+qr+qs+rs)/(\root[3]{3\sqrt(24(pq+pr+ps+qr+qs+rs)^3+81(pqr+qrs+rsp+spq)^2)+27(pqr+qrs+rsp+spq)})<s`
Nhìn đề đến một người theo Toán như anh còn thấy nản í :)
ừ thì năm nay lên 11 nma toi đ hiểu đây là cgi =))
#include <bits/stdc++.h>
using namespace std;
long long pow(long long n,long long count,long long root,long long x)
{
count =0;
for (int i=0;i<n;i++)
{
root=(int) sqrt(x);
if (root*root==x)
count++;
}
Cho mình hỏi vấn đề bài này là gì ạ ?