2x²+16x+2 Don't start out trying to use the AC method first. Always look for a common factor first. The AC method will wait till later -- if it can be used at all. First factor out the common factor 2: 2(x²+8x+1) As it turns out it is not factorable any further. So the AC method will not work here. So the final factored form is simply 2(x²+8x+1) Edwin