Tìm x
a) 3x = 94/273
b) 55/5x = 518
Tìm x
a, (x+2).(x\(^2\)-2x+4)+x(5-x)(x+5)=-17
b, 3x\(^2\)-5x+2=0
Tìm x
a, 2x.(x-3)+3(x-3)=0
b, x(3x-1)-5(1-3x)=0
a) \(2x\left(x-3\right)+3\left(x-3\right)=0\)
\(\Leftrightarrow\left(x-3\right)\left(2x+3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=0\\2x+3=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-\dfrac{3}{2}\end{matrix}\right.\)
b) \(x\left(3x-1\right)-5\left(1-3x\right)=0\)
\(\Leftrightarrow x\left(3x-1\right)+5\left(3x-1\right)=0\)
\(\Leftrightarrow\left(3x-1\right)\left(x+5\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}3x-1=0\\x+5=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}\\x=-5\end{matrix}\right.\)
bài 1 tìm x
a)\(\sqrt{10x+20}\)
b)\(\sqrt{\dfrac{99}{4x-1}}\)
c)\(\sqrt{\dfrac{-5x-10}{2021}}\)
a)
\(=\sqrt{10\left(x+2\right)}=\sqrt{10}.\sqrt{x+2}\)
\(\sqrt{x+2}\ge0=>x+2\ge0=>x\ge-2\)
b)
\(=\dfrac{\sqrt{99}}{\sqrt{4x-1}}\)
\(=>4x-1>0=>4x>1=>x>\dfrac{1}{4}\)
c)
\(=\dfrac{\sqrt{-5x-10}}{\sqrt{2021}}=>-5x-10\ge0\)
\(=>-5\left(x+2\right)\ge0\)
\(=>x+2\ge0=>x\ge-2\)
a: ĐKXĐ: \(x\ge-2\)
b: ĐKXĐ: \(x>\dfrac{1}{4}\)
c: ĐKXĐ: \(x\le-2\)
Tìm x
a) 5x+5x+2=650
b) 3x.1+5.3x.1=162
\(a,5^x+5^{x+2}=650\\ \Rightarrow a,5^x+5^x.25=650\\ \Rightarrow26.5^x=650\\ \Rightarrow5^x=25\\ \Rightarrow5^x=5^2\\ \Rightarrow x=2\)
\(b,3^{x.1}+5.3^{x.1}=162\\ \Rightarrow3^x+5.3^x=162\\ \Rightarrow6.3^x=162\\ \Rightarrow3^x=27\\ \Rightarrow3^x=3^3\\ \Rightarrow x=3\)
a: \(\Leftrightarrow5^x=25\)
hay x=2
a, <=> 5x + 5x .52 =650
<=> 5x +25.5x =650
<=> 26.5x =650
<=> 5x =25
<=> 5x = 52
<=> x=2
b, <=> 6. 3x =162
<=> 3x =27
<=> 3x =33
<=> x=3
Chúc bạn học tốt nha!
A. Tìm GTLN của -5x^2-4x+1
B. Tìm GTNN của 2x^2+3x+1
Tìm GTLN của C=-5x^2-4x+1
Tìm GTNN của B=2x^2+3x+1
tìm x
a. (2x + 1) ² - (3x - 4) ² = 0
b. 5x ³ - 3x ² + 10x - 6 = 0
a) Ta có: \(\left(2x+1\right)^2-\left(3x-4\right)^2=0\)
\(\Leftrightarrow\left(2x+1-3x+4\right)\left(2x+1+3x-4\right)=0\)
\(\Leftrightarrow\left(5-x\right)\left(5x-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=\dfrac{3}{5}\end{matrix}\right.\)
b) Ta có: \(5x^3-3x^2+10x-6=0\)
\(\Leftrightarrow x^2\left(5x-3\right)+2\left(5x-3\right)=0\)
\(\Leftrightarrow5x-3=0\)
hay \(x=\dfrac{3}{5}\)
tìm x
a) 4(18-5x)-12(3x-7)=15(2x-16)-6(x+14)
b) 5(3x+5)-4(2x-3)=5x+3(2x+12)+1
c) 2(5x-8)-3(4x-5)=4(3x-4)+11
a) \(\Rightarrow72-20x-36x+84=30x-240-6x-84\)
\(\Rightarrow80x=480\Rightarrow x=6\)
b) \(\Rightarrow15x+25-8x+12=5x+6x+36+1\)
\(\Rightarrow4x=0\Rightarrow x=0\)
c) \(\Rightarrow10x-16-12x+15=12x-16+11\)
\(\Rightarrow14x=4\Rightarrow x=\dfrac{2}{7}\)
Tìm x
a, x\(^2\)-8x+6=0
b,\(\dfrac{2x-1}{3}+\dfrac{x}{5}=\dfrac{3x}{10}\)
\(a,\Leftrightarrow\left(x^2-8x+16\right)-10=0\\ \Leftrightarrow\left(x-4\right)^2-10=0\\ \Leftrightarrow\left(x-4-\sqrt{10}\right)\left(x-4+\sqrt{10}\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=4+\sqrt{10}\\x=4-\sqrt{10}\end{matrix}\right.\\ b,\Leftrightarrow10\left(2x-1\right)+6x=9x\\ \Leftrightarrow20x-10-3x=0\\ \Leftrightarrow17x=10\Leftrightarrow x=\dfrac{10}{17}\)
tìm gtnn của
E= 3x^2-5x+1
E = 3( x2 - 5x/4 + 25/4) -25/4 +1
GTNN E = -21/4