Hi there!
Let x be the unknown number
The key here is to pay attention to the question. One-half of a number decreased by 16.
To find half of a number, we can divide that number by 2 or, if it makes more sense to you, multiply the number by 1/2. It would be x/2.
Decreased by 16 means to just subtract 16 from x/2.
X/2-16=0
We can solve for x by isolating the variable and moving terms over the equal sign.
X/2-16=0
X/2=16
X=16*2
X=32
Hope this helps!