B. Subtracting with Algebra Tiles

Represent the first expression using algebra tiles.

Subtract $x^2-2x-5$ by removing $x^2$, $-2x$, and $-5$.

There are no −1 tiles to remove, so it is necessary to introduce five pairs of −1 and 1 tiles. These pairs add to zero, so adding them does not change the value of the expression.

Remove five of the −1 tiles.

Use the remaining tiles to determine the difference between the original two expressions.

  $(2x^2-4x+3)-(x^2-2x-5)=x^2-2x+8$