64²-36²=(64+36) (64-36)=
= 100*28=2800
86² -14² = (86+14)(86-14)=
=100*72=7200
328² -172² = (328+172)(328-176)=
= 500*152= 76000
328²- 172 : 2 = 107584 - 86 =
= 107498
64²-36²=(64+36) (64-36)=
= 100*28=2800
86² -14² = (86+14)(86-14)=
=100*72=7200
328² -172² = (328+172)(328-176)=
= 500*152= 76000
328²- 172 : 2 = 107584 - 86 =
= 107498