Question

Tính nhanh:

a) 4.13.6+12.76.2+11.8.3

b) 2-4+6+8+10-12+...+98-100

c) (2+4+6+...+100) . (36.333-108-111)

d) 1-2-3+4+5-6-7+...+97-98-99+100

Answer 1

a) = 13 x 24 + 24 x 76 + 11 x 24 d)= (1-2-3+4)+(5-6-7+8)+...+(97-98-99+100)

= 24 x ( 13 + 76 + 11 ) = 0 + 0 +...+ 0

= 24 x 100 =0

= 2400

CÓ VIỆC BẬN NÊN MÌNH CHỈ LÀM ĐC ĐẾN ĐÓ THÔI !

Answer 2

d) 1-2-3+4+5-6-7+...+97-98-99+100

=(1-2-3+4)+(5-6-7+8)+(9-10-11+12)+......+(97-98-99+100)

=0+0+0+0+.....+0

=0

Vay bang 0

Answer 3

c) (2+4+6+...+100) . (36.333-108-111)

Ta chia hai tich tren la A va B, ta co:

A=(2+4+6+...+100)

B=(36.333-108-111)

A co ssh la:(100-2):2+1=45(ssh)

B=36.333-108-111

=>

A=(100+2)x45:2=2295

B=36.(111.3)-108-111=111.(36.3)-108-111=111.108-108.1-111=(111.8-108.1)-111=11880-111=11769

=>

A.B =2295.11769=( bam may tinh )27009855