Đặt \(\sqrt{5x^2+6x+5}=a,4x=b\left(a\ge0\right)\)
Khi đó Pt
<=> \(a\left(a^2+1\right)=b\left(b^2+1\right)\)
<=>\(\left(a-b\right)\left(a^2+ab+b^2+1\right)=0\)
MÀ \(a^2+ab+b^2+1>0\)
=> \(a=b\)
=> \(\sqrt{5x^2+6x+5}=4x\)
=> \(\hept{\begin{cases}x\ge0\\11x^2-6x-5=0\end{cases}}\)
=>\(x=1\)
Vậy x=1