assume the number is x
now, we will translate the written english into equation:
seven minus 2 times the number is 7-2x
the number minus 2 is x-2
we will equate these two equations (the question says that they are equal) ans solve for x as follows:
7-2x=x-2
7+2=x+2x
9=3x
x=3
the required number is 3