Giải các ptr saua, ( x + 1 )2 - 4( x2 - 2x + 1 ) = 0b, 9( x - 2 )2 - 4( x - 1)2 = 0c, 2x2 - 3( 2x - 3 )2 = 0d, x2 - 4x + 3 = 0e, x2 + 6x +16 = 0f, 7x2 + 12x + 5 = 0g, 3x2 - 5x +8 = 0h, 5x2 - 3x + 15 = 0i, x2 - 4x +1 = 0k, 3x2 + 7x + 2 = 0l. 5x2 - \(\frac{10}{7}x\)+ \(\frac{5}{49}\) = 0m, ( 5 - \(\sqrt{2}\))x2 - 10x + 5 + \(\sqrt{2}\) =...
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Giải các ptr sau
a, ( x + 1 )2 - 4( x2 - 2x + 1 ) = 0
b, 9( x - 2 )2 - 4( x - 1)2 = 0
c, 2x2 - 3( 2x - 3 )2 = 0
d, x2 - 4x + 3 = 0
e, x2 + 6x +16 = 0
f, 7x2 + 12x + 5 = 0
g, 3x2 - 5x +8 = 0
h, 5x2 - 3x + 15 = 0
i, x2 - 4x +1 = 0
k, 3x2 + 7x + 2 = 0
l. 5x2 - \(\frac{10}{7}x\)+ \(\frac{5}{49}\) = 0
m, ( 5 - \(\sqrt{2}\))x2 - 10x + 5 + \(\sqrt{2}\) = 0
b)\(9\left(x-2\right)^2-4\left(x-1\right)^2=\left(9x^2-36x+36\right)-\left(4x^2+8x-4\right)\)
\(=9x^2-36x+36-4x^2+8x-4\)
\(=5x^2-28x+32\)
\(=\left(x-5\right)\left(5x-8\right)\)
\(\hept{\begin{cases}x-5=0\\5x-8=0\end{cases}\Rightarrow}\hept{\begin{cases}x=5\\x=\frac{8}{5}=1\frac{3}{5}\end{cases}}\)
a) \(\left(x+1\right)^2-4\left(x^2-2x+1\right)=0\)
\(\left(x^2+2x+1\right)-\left(4x^2-8x+4\right)=0\)
\(-3x^2+10x-3=0\)
\(\left(3-x\right)\left(3x-1\right)=0\)
\(\hept{\begin{cases}3-x=0\\3x-1=0\end{cases}}\)
\(\hept{\begin{cases}x=3\\x=\frac{1}{3}\end{cases}}\)