Respuesta :

-4 and -5
because to get 16 to 12 you have to subtract 4 but it wants you to add so you put a negative sign infront of it.

and a negative multiply by a negative equals a positive so -3×-5=15

Answer:

1.x=-4

2. x=-5

Step-by-step explanation:

16+x=12

Subtract 16 from each side

16+x-16 = 12-16

x = -4


-3x=15

Divide each side by -3

-3x/-3 = 15/-3

x = -5