Question

-12+(x-9)=0

Answer 1

-12+(x-9)=0

x-9=12

x=12+9

x=21

Answer 2

-12+(x-9)=0

(x-9)=0-(-12)

(x-9)=12

x=12+9

x=21

Answer 3

-12+(x-9)=0

=>x-9=0-(-12)

=>x-9=12

=>x=12+9

=>x=21

Answer 4

-12+(x-9)=0

x-9=0-(-12)

x-9=12

x=12+9

x=21