lets say your number is X
so we need to know what x equals
so
here are the parts and how they would be translated
-64 is
-64=
4 times the number
4x
12 more than
+12
Now put it together to get the equation
-64=4x+12
Then you can solve for x
subtract 12 from both sides
-76=4x
divde both sides by 4
x=-19