(8b2+6b-1) (8b2-8b+7)
=(8b2+6b+−1)(8b2+−8b+7)=(8b2)(8b2)+(8b2)(−8b)+(8b2)(7)+(6b)(8b2)+(6b)(−8b)+(6b)(7)+(−1)(8b2)+(−1)(−8b)+(−1)(7)=64b4−64b3+56b2+48b3−48b2+42b−8b2+8b−7Answer:=64b4−16b3+50b−7