Respuesta :

Answer:

x = ± [tex]\sqrt{7}[/tex]

Step-by-step explanation:

3x² + 7 = 28 ( subtract 7 from both sides )

3x² = 21 ( divide both sides by 3 )

x² = 7 ( take square root of both sides )

x = ± [tex]\sqrt{7}[/tex]

that is x = - [tex]\sqrt{7}[/tex] , x = [tex]\sqrt{7}[/tex]

Answer:

A. +[tex]\sqrt{7}[/tex]

Step-by-step explanation:

3x^2+7=28
3([tex]+\sqrt{7} ^{2}[/tex] )+7=28

3(7)+7=28

21+7=28
28=28

Hope it helps