6. Brady is incorrect. the 2.6x - (1.3x - 4.5) should be simplified to 2.6x - 1.3x + 4.5 which is simplified to 1.3x + 4.5 (Should be + 4.5 not - 4.5)
7. Fay and Khai are both correct. Jamie is not. The perimeter is adding all four sides together. so 2x+2x+x+10+x+10 or 2(2x)+ 2(x+10) both work. when you simplify that, though, it should be 4x+2x+10 which is actually 6x+10. Jamie did not add the 2x. :)
