Question

9z²+12z+4=64 baskara​

Answer 1

Resposta:

z= -10/3 ou z=2

Explicação passo-a-passo:

9z²+12z+4=64

9z²+12z+4-64=0

9z²+12z-60=0 ÷(3)

3z²+4z-20=0

$Aplicando~a~f\'{o}rmula~de~Bhaskara~para~3z^{2}+4z-20=0~~\\e~comparando~com~(a)z^{2}+(b)z+(c)=0,~temos~a=3{;}~b=4~e~c=-20\\\\\Delta=(b)^{2}-4(a)(c)=(4)^{2}-4(3)(-20)=16-(-240)=256\\\\z^{'}=\frac{-(b)-\sqrt{\Delta}}{2(a)}=\frac{-(4)-\sqrt{256}}{2(3)}=\frac{-4-16}{6}=\frac{-20\div2}{6\div2}=-\frac{10}{3} \\\\z^{''}=\frac{-(b)+\sqrt{\Delta}}{2(a)}=\frac{-(4)+\sqrt{256}}{2(3)}=\frac{-4+16}{6}=\frac{12}{6}=2\\\\S=\{-\frac{10}{3} ,~2\}$