# Welcome to Linear Transformation

Algebra Level 5

Let $$j: \mathbb{R^2} \rightarrow \mathbb{R^2}$$ be the linear operator defined by $$(x,y) \rightarrow (x + 2y, -y)$$. If $$A = Mat_{E}(j)$$ where $$E =$${$$(1,0),(0,1)$$}. Find $$-|A|$$.

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