The area (in square meters),a, of a yard is given by the expression:
a = x^4+18x^2+81
Where x is a positive integer and each dimension is greater than 1 meter. What are two (not necessarily unique) expressions that could represent the dimensions of the yard ?
In the answer box, write these two expressions as a product that equals the area (e.g. "(expression 1)(expression 2)").