Question

Resolva as questões incompletas do 2° grau: 3x²-20=7​

Answer 1

Resposta:

$3x {}^{2} - 20 = 7 \\ 3 {x}^{2} = 7 + 20 \\3 {x}^{2} = 27 \\ {x}^{2} = 9 \\ x = \sqrt{9} \\ x = + - 3 \\ x {}^{1} = + 3 \\ {x}^{2} = - 3$

Answer 2

${3x}^{2} - 20 - 7 = 0 \\ {3x }^{2} - 27 = 0 \\ Δ = 0 - 4 \times 3 \times - 27 \\ Δ = - 12 \times - 27 \\ Δ = 324 \\ x = + - \frac{ \sqrt{324} }{2 \times 3} = + - \frac{18}{6}$

x'=+18/6

x"=-18/6