Question

CHứng tỏ:

1.3.5.7.9...97.99 = 51/2 . 52.2 . 53/2 ... 99/2 . 100/2

Answer 1

đặt A = 1.3.5.7.9...97.99,B=51/2 . 52/2 . 53/2 ... 99/2 . 100/2

A=1.3.5.7.9....97.99

=1.3.5.7.....97.99.2.4.6...100/2.4.6...100

=1.2.3.4.5...100/2.1.2.2.2.3.2.4...2.50

=1.2.3.4.5...100/1.2.3.4...50.2.2.2...2(50 chữ số 2)

=51.52.53...100/2.2.2.2...100

B=51/2.52/2.53/2...99/2.100/2

Suy ra A=B

Answer 2

bó tay chấm com!

Answer 3

Bạn nhân cả 2 vế với 1 lượng 2 . 4 . 6 ..... 98 . 100