Question

Resolva a equação incompleta do 2 grau .

a)  3x²-4 =0      b) 5x²+7 =0  c) 7x² =28

 

Answer 1

a)

$3x^2-4 = 0\\\\3x^2 = 4\\\\x^2 = \frac{4}{3} \\\\x = \pm \sqrt{ \frac{4}{3} } \\\\x = \pm \frac{2}{ \sqrt{3} } \\\\\boxed{x = \pm \frac{2 \sqrt{3} }{3} }$

b)

$5x^2+7 = 0\\\\5x^2 = -7\\\\x^2 = \frac{-7}{5} \\\\x = \pm \sqrt{ \frac{-7}{5} }\\\\\boxed{ x = \{\}}$

c)

 $7x^2 = 28 \\ \\ x^2 = 4\\\\x = \pm \sqrt{4}\\\\\boxed{x = \pm2 }$

Espero ter ajudado. :))