An algebra tile configuration. Outside of the configuration are the following tiles: x squared, x, negative x, , and negative. 0 tiles are in the Factor 1 spot and 0 tiles are in the Factor 2 spot. 9 tiles are in the Product spot in 5 columns with 5 rows. First row: 1 x squared, 4 x. Below the x squared tile are 4 x tiles. What constant term is necessary to complete the perfect square trinomial pictured in the algebra tiles? x2 8x.