The correct option is D - 5x - 3xy - 2zx - 3y
Let 's' be the term to be added to (6xy + 3y +7x + 2zx) to get (2x + 3xy).
(6xy + 3y +7x + 2zx) + s = (2x + 3xy)
Subtract (6xy + 3y +7x + 2zx) from (2x + 3xy),
2x + 3xy + 0zx + 0y
7x + 6xy + 2zx + 3y
(-) (-) (-) (-)
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- 5x - 3xy - 2zx - 3y