Respuesta :

Answer:

C) x = -2

Step-by-step explanation:

Original equation:

[tex]12+\sqrt{1-4x}=15\\[/tex]

subtract 12 from both sides:

[tex]\implies \sqrt{1-4x}=3[/tex]

square both sides:

[tex]\implies 1-4x=9[/tex]

subtract 1 from both sides:

[tex]\implies -4x=8[/tex]

divide both sides by -4:

[tex]\implies x=-2[/tex]

[tex]\\ \tt\rightarrowtail 12+\sqrt{1-4x}=15[/tex]

[tex]\\ \tt\rightarrowtail \sqrt{1-4x}=3[/tex]

[tex]\\ \tt\rightarrowtail 1-4x=3^2[/tex]

[tex]\\ \tt\rightarrowtail 1-4x=9[/tex]

[tex]\\ \tt\rightarrowtail -4x=8[/tex]

[tex]\\ \tt\rightarrowtail x=-2[/tex]