Answer:
A 3
Step-by-step explanation:
Let n = the number
a number decreased by 12
n-12
This is equal to 3 times the opposite =
3 times the opposite
3*(-n)
-3n
Setting the two parts equal
n-12 = -3n
Subtract n from each side
n-n-12 = -3n-n
-12 = -4n
Divide by -4
-12/-4 = -4n/-4
3 =n
