Respuesta :

arsemagetachew14

Twice means two times

18.9 - 2x = 9.9

18.9 -18.9 -2x=9.9 - 18.9

-2x=9.9 - 18.9

(-2x= -9) divide both sides by negative two

-2x/-2 = -9/-2

x=4.5