51²x 50-49² x50
= 50 x (51²-49² )
= 50 x (51+49 ) ( 51-49)
= 50 x 100 x 2
= 10000
施主,我看你骨骼清奇,
器宇轩昂,且有慧根,
乃是万中无一的武林奇才.
潜心修习,将来必成大器,
鄙人有个小小的考验请点击在下答案旁的
"选为满意答案"