Question

How do you find the missing number or term to make a perfect square trinomial. `x^2 - 18x +___`?

Answer 1

`81`

Explanation:

If you use `81` you get:
`x^2-18x+81=(x-9)^2`
It has to be a number that multiplied by `2` gives `18`; this is `9` that has to appear squared in your missing place.