(2x+3)\(^2\) = \(\frac{25}{9}\)
=> 2x+3 = \(\frac{5}{3}\)
=> 2x = \(\frac{5}{3}\) - 3
=> 2x = \(-\frac{4}{3}\)
=> x =\(-\frac{2}{3}\)
Hai trường hợp nha vì 25/9=(\(\frac{-5}{3}\))^2 và =(\(\frac{5}{3}\))^2
\(\frac{9\cdot\left(2x+3\right)^2}{9}=\frac{25}{9}\)
\(9\cdot\left(4x^2+12x+9\right)=25\)
\(36x^2+108x+81=25\)
\(6x^2+2\cdot6x\cdot9+9^2-25=0\)
\(\left(6x+9\right)^2-5^2=0\)
\(\left(6x+9-5\right)\left(6x+9+5\right)=0\)
\(6x+4=0\) hoặc \(6x+14=0\)
\(6x=-4\) \(6x=-14\)
\(x=\frac{-2}{3}\) \(x=\frac{-7}{3}\)
\(\frac{25}{9}\)sao mak bằng \(\frac{5}{3}\)được
TH2: (2x+3)\(^2\) =\(\frac{29}{5}\)
=> 2x+3 = \(-\frac{5}{3}\)
=> 2x = \(-\frac{5}{3}\) - 3
=> 2x = \(-\frac{14}{3}\)
=> x = \(-\frac{7}{3}\)
mạnh ez (2x+3)2 = \(\frac{29}{5}\)
=> (2x+3)2 = (\(\frac{25}{9}\))2
=> 2x+3 = \(\frac{5}{3}\)