Respuesta :

Answer:

Equation: x-(-2)=21

Solution: x=19

Step-by-step explanation:

A number decreased by -2 is equal to 21.

Let's call the number,x. Decreased means we are going to subtract.

x-(-2)=21

-(-2) is just +2:

x+2=21

Subtract 2 on both sides:

x=21-2

Simplify:

x=19

So if 19 is decreased by -2 we should get 21.