Question

Me ajundem
(2x - 1)² = - 8 (2x + 1 )

Answer 1

Resposta:

x= -3/2

Explicação passo-a-passo:

(2x - 1)² = - 8 (2x + 1 )

4x²-4x+1= -16x-8

4x²+12x+9=0

$Aplicando~a~f\'{o}rmula~de~Bhaskara~para~4x^{2}+12x+9=0~~\\e~comparando~com~(a)x^{2}+(b)x+(c)=0,~temos~a=4{;}~b=12~e~c=9\\\\\Delta=(b)^{2}-4(a)(c)=(12)^{2}-4(4)(9)=144-(144)=0\\\\x^{'}=\frac{-(b)-\sqrt{\Delta}}{2(a)}=\frac{-(12)-\sqrt{0}}{2(4)}=\frac{-12-0}{8}=\frac{-12\div4}{8\div4}=-\frac{3}{2}\\\\x^{''}=\frac{-(b)+\sqrt{\Delta}}{2(a)}=\frac{-(12)+\sqrt{0}}{2(4)}=\frac{-12+0}{8}=\frac{-12\div4}{8\div4}=-\frac{3}{2}\\\\S=\{-\frac{3}{2},~-\frac{3}{2}\}$