Tim x
9x : 3x= 3
3x+3x×33=756
Giải các PTLG sau:
\(tan^23x+tan3x\cdot tan9x=2\)
\(tan^33x+cot^33x+cot^36x=\dfrac{11}{6}\)
\(tan^22x-tan2x\cdot tan6x=2\)
\(tan^3x+cot^3x+cot^9x=\dfrac{11}{3}\)
Giải Phương trình
\(3x\left(3x^2-6x-1\right)-x\left(9x^2-9x-2\right)-\left(3x+1\right)^2=33\)
Help me
Cần gấp trong hôm nay
x+2x+3x+3x+4x+5x+6x+7x+8x+9x+10x=-165.tim x
X*(1+2+3+4+5+6+7+8+9+10)=-165
X*55=-165
X=-165/55=-3
111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
(1x + 9x) + (2x + 8x) + (3x + 7x) + (4x + 6x) + 5x + 10x = -165
10x^6 + 5x = -165
= 65x (-165)
= -100
Tim gtnn, gtln neu co:
A= 3x^2 +9x+17/3x^2 + 9x+7
B= 2x^2-16x+41/x^2-8x+22
C= -16/5x^2 + 20x + 26
D= 1/3x^2 - 9x +15
\(A=\dfrac{3x^2+9x+17}{3x^2+9x+7}=1+\dfrac{10}{3x^2+9x+7}=1+\dfrac{10}{3\left(x^2+2.x.\dfrac{9}{2}+\dfrac{81}{4}\right)-\dfrac{215}{4}}\\ =1+\dfrac{10}{3\left(x+\dfrac{9}{2}\right)^2-\dfrac{215}{4}}\le\dfrac{35}{43}\)
Câu khác giải TT
Tổng tất cả các nghiệm của phương trình:
\(\sqrt{9x^2+33x+28}+5\sqrt{4x-3}=5\sqrt{3x+4}+\sqrt{12x^2+19x-21}\)
\(\sqrt{9x^2+33x+28}+5\sqrt{4x-3}=5\sqrt{3x+4}+\sqrt{12x^2+19x-21}\)
\(\Leftrightarrow\sqrt{\left(3x+4\right)\left(3x+7\right)}+5\sqrt{4x-3}=5\sqrt{3x+4}+\sqrt{\left(3x+7\right)\left(4x-3\right)}\)
\(\Leftrightarrow\sqrt{\left(3x+4\right)\left(3x+7\right)}-5\sqrt{3x+4}=\sqrt{\left(3x+7\right)\left(4x-3\right)}-5\sqrt{4x-3}\)
\(\Leftrightarrow\sqrt{3x+4}\left(\sqrt{3x+7}-5\right)=\sqrt{4x-3}\left(\sqrt{3x+7}-5\right)\)
\(\Leftrightarrow\sqrt{3x+4}\left(\sqrt{3x+7}-5\right)-\sqrt{4x-3}\left(\sqrt{3x+7}-5\right)=0\)
\(\Leftrightarrow\left(\sqrt{3x+7}-5\right)\left(\sqrt{3x+4}-\sqrt{4x-3}\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}\sqrt{3x+7}=5\\\sqrt{3x+4}=\sqrt{4x-3}\end{cases}}\)\(\Leftrightarrow\orbr{\begin{cases}3x+7=25\\3x+4=4x-3\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=6\\x=7\end{cases}}\) (thỏa mãn). Suy ra tổng các nghiệm của pt là \(6+7=13\)
tim x:(5x-7-9x):(-2-3x+7)=5-2(x-2)
tim x
3x(12x-4)-9x(4x-3)=30
\(3x\left(12x-4\right)-9x\left(4x-3\right)=30\)
=>\(36x^2-12x-36x^2+17x=30\)
=>\(17x-12x=30\)
=>\(5x=30\)
=>x=30:5
=>x=6
\(3.\left(12x-4\right)-9.\left(4x-3\right)=30\)
\(\Rightarrow36x-12-36x+27=30\)
\(\Rightarrow36x-36x=30+12-27\)
\(\Rightarrow x.\left(36-36\right)=15\)
\(\Rightarrow x.0=15\)
\(\Rightarrow x=15:0\) \(???\)
ĐỀ bài sai rồi
tim so tu nhien x thoa man :(9x+17):(3x+2).tra loi x=
tim so nguyen x, y thoa man 3x - 13 = y(9x-13)
Tim x
9x^2-4-2(3x-2)^2=0