Respuesta :

Answer:

40-b

Step-by-step explanation:

x is the unknown number

x+b = 40

We want to find x

Subtract b from each side

x+b-b = 40 -b

x = 40-b

The unknown number is 40-b

Answer:

[tex]\huge \boxed{40-b}[/tex]

Step-by-step explanation:

[tex]\sf Let \ x \ be \ that \ number.[/tex]

[tex]x+b=40[/tex]

[tex]\sf Solve \ for \ x.[/tex]

[tex]\sf Subtract \ b \ from \ both \ sides.[/tex]

[tex]x+b-b=40-b[/tex]

[tex]\sf Simplify \ the \ equation.[/tex]

[tex]x=40-b[/tex]