1) (а+b)"3"("..." так я буду писать степень, в кавычках) - (а -b)"3"- 8b"3"= a"3" + 3a"2"b+3ab + b"3"-(a"3'-3a"2"b+3ab"2"-b"3")- 8b"3"= 6a"2"b-6b"3"
2)(a"2"+b"2")"2"- ( a"2"-b"2")"2"-a"2"= 2b"2"• 2a"2"-a"2"= 4a"2"b"2"-a"2"
3)(a"4"+b"4")"2" -(a"4"-b"4")"2"- a"2"b"2"= 2b"4"• 2a"4"-2a"2"b"2"= 4a"4"b"4"-a"2"b"2"