Respuesta :

[tex] \sf \longmapsto \: 2x + 21 = 3[/tex]

[tex]\sf \longmapsto2x = 3 - 21[/tex]

[tex]\sf \longmapsto2x = - 18[/tex]

[tex]\sf \longmapsto \: x = \frac{ - 18}{2} [/tex]

[tex]\sf \longmapsto x = - 9[/tex]

Answer:

[tex]\bf x=-9[/tex]

Step-by-step explanation:

[tex]\sf 2x+21=3[/tex]

Subtract 21 from both sides:-

[tex]\sf 2x+21-21=3-21[/tex]

Simplify

[tex]\sf 2x=-18[/tex]

Divide both sides by 2:-

[tex]\sf \cfrac{2x}{2}=\cfrac{-18}{2}[/tex]

[tex]\sf x=-9[/tex]