tính nhanh
(1+1/105)*(1+1/106)*(1+1/107)*(1+1/108)*(1+1/109)
Tính nhanh:
( 1 + 1/105 ) x ( 1 + 1/106 ) x ( 1+ 1/107 ) x ( 1+ 1/108 ) x ( 1+ 1/109 )
\(=\frac{106}{105}.\frac{107}{106}.\frac{108}{107}.\frac{109}{108}.\frac{110}{109}\)
\(=\frac{106.107.108.109.110}{105.106.107.108.109}\)
\(=\frac{110}{105}=\frac{22}{21}.\)
Tính nhanh:
( 1 + 1/105 ) x ( 1 + 1/106 ) x ( 1+ 1/107 ) x ( 1+ 1/108 ) x ( 1+ 1/109 )
\(=\frac{106}{105}\times\frac{107}{106}\times\frac{108}{107}\times\frac{109}{108}\times\frac{110}{109}\)
\(=\frac{110}{105}=\frac{22}{21}\)
Tính nhanh:
( 1 + 1/105 ) x ( 1 + 1/106 ) x ( 1+ 1/107 ) x ( 1+ 1/108 ) x ( 1+ 1/109 )
tính nhanh
(1+1/105)x(1+1/106)x(1+1/107)x(1+1/108)x(1+1/109)
(1+1/105)x(1+1/106)x(1+1/107)x(1+1/108)+(1+1/109)
=109/105+110/109
=23431/11445
Cho A = 1/2+1/3+1/4+...+1/108+1/109 và B =108/1+107/2+106/3+...+2/107+2/108. Tính A/B
1.tính
101-102-103-(-104)-105-106-(-107)-108-(-109)-(-110)
tính bằng 2 cách
Giúp mik vs ạ mik đag cần gấp ạ 🥺🥺🥺
=101-102-103+104-105-106+107-108+109+110
= (101+104+107+109+110)-(102+103+105+106+108)
=701-704
=-3
b1 :tính
a) 101 - 102 - (-103) - 104 - (-105) - 106 - (-107) - 108 - 109
b) ( a-1 ) - ( a-3 )
c) (2+b) - ( b+1)
a: =(-1)+(-1)+(-1)+(-1)-109=-113
b: =a-1-a+3=2
c: =b+2-b-1=1
b1 :tính
a) 101 - 102 - (-103) - 104 - (-105) - 106 - (-107) - 108 - 109
b) ( a-1 ) - ( a-3 )
c) (2+b) - ( b+1)
ý a dễ r` k làm nữa, lm ý b, c thui nha!
b) (a-1) - (a - 3) = a - 1 - a + 3
= (a - a)+ (- 1 + 3) = 0 + 2 = 2
c) ( 2 + b) - (b + 1)
= 2 + b - b - 1 = ( b - b) + ( 2 - 1)
= 0 + 1 = 1
a) 101-102+103-104+105-106+107-108-109
=(101-102)+(103-104)+(105-106)+(107-108)-109
=(-1)-1-1-1-109
=(-4)-109
=-113
b) (a-1)-(a-3)
=a-1-a+3
=(a-a)+(-1+3)
=0+2
=2
c) (2+b)-b-1
=(b-b)+(2-1)
=0+1
=1
cho a=1/2+1/3+1/4+...+1/108+1/109 va b= 108/1+107/2+106/3+...+2/101+1/108 tinh a/b