Expand the brackets to create an equation. (2x+7)(x-3)

shown using a diagram during interview
using the crab claw method, multiplying the correct components with one another, displaying how to set it out neatly and correctly to the benefit of the examiner.
= 2x^2-6x+7x-21 (asking student: can it be simplified?)= 2x^2+x-21 (asking student: is this the final form?)