The proof that the area of the trapezium is 2x² + x -351 = 0 can be seen in the image attached below.
<h3>What is a trapezium?</h3>A trapezium is a quadrilateral that has a pair of opposite parallel sides.
From the given diagram:
The area of the trapezium can be computed as;
351 = 2x² + x
2x² +x - 351 = 0 : Proved
Learn more about the area of trapezium here:
brainly.com/question/16904048