Answer:
[tex]x=\frac{2}{3} , -2[/tex]
Step-by-step explanation:
[tex]4(9x^{2} +12x+4)=64[/tex]
[tex]36x^{2} +48x+16 = 64[/tex]
[tex]36x^{2} +48x-48=0[/tex]
[tex]12(3x-2)(x+2)=0\\[/tex]
