Question

Hu

求解

若(a+b)= 15129,(a-b)= 5329,則
ab = ?
0
车
²b²²
C

試計算下列各式:
(1) (5−1) (5+1) (5²+1) (5¹+1 ) +1 = ?
(以指數表示)+50
(2) 1×3×(2²+1 ) (2¹+1 ) ( 2³+1) = 2″−1,
求n=?
解
175+47/5³1/54
D
+

Answer 1

YANNNNNNNN

1.(a+b)² = a²+2ab+b² (a-b)² = a²-2ab+b²
(a+b)²-(a-b)² = a²+2ab+b²-(a²-2ab+b²)
=4ab
由上述得知 15129-5329=9800 9800÷4=ab
故ab為2450