tính nhanh :
a) 2017x34+2017x65+2017=
b) 2007-(0x3/4x1/4)=
Tính nhanh
a) 2017 × 34 + 2017 × 66
b ) 2007 – ( 0 × 3 4 × 1 4 )
Tính:(1-1/2x1/2)x(1-1/3x1/3)x(1-1/4x1/4)x…x(1-1/2007x1/2007)
(1-1/2x1/2)x(1-1/3x1/3)x(1-1/4x1/4)x…x(1-1/2007x1/2007) = ( 1 - 1/4 ) x ( 1 - 1/9 ) x ( 1- 1/16) x .....x ( 1 - 1/4028049) = 3/4 x 8/9 x 15/16 x .....x 4028048 / 4028049 = 3 x 8 x 15 x .....x 4028048 / 4 x 9 x 16 x ......x 4028049 = 1 x 3 x 2 x 4 x 3 x 5 x .....x 2006 x 2008 / 2x2 x 3 x3 x 4 x 4 x .....x 2007 x 2007 = ( 1 x 2 x 3 x .....x 2006) x ( 3 x 4 x 5 x .....x 2008) / ( 2 x 3 x 4 x ....x 2007) x ( 2 x 3 x 4 x ....x 2007) = 2008 / 2007 x 2 = 1004 / 2007
Tính:
(1-1/2x1/2)x(1-1/3x1/3)x(1-1/4x1/4)x…x(1-1/2007x1/2007)
(1-1/2x1/2)x(1-1/3x1/3)x(1-1/4x1/4)x…x(1-1/2007x1/2007)
= ( 1 - 1/4 ) x ( 1 - 1/9 ) x ( 1- 1/16) x .....x ( 1 - 1/4028049)
= 3/4 x 8/9 x 15/16 x .....x 4028048 / 4028049
= 3 x 8 x 15 x .....x 4028048 / 4 x 9 x 16 x ......x 4028049
= 1 x 3 x 2 x 4 x 3 x 5 x .....x 2006 x 2008 / 2x2 x 3 x3 x 4 x 4 x .....x 2007 x 2007
= ( 1 x 2 x 3 x .....x 2006) x ( 3 x 4 x 5 x .....x 2008) / ( 2 x 3 x 4 x ....x 2007) x ( 2 x 3 x 4 x ....x 2007)
= 2008 / 2007 x 2
= 1004 / 2007
TÍNH
A,|X-3 Y|^2007+|Y+4|^2008
B,(X+Y)^2016+2017.|Y-1|
a)[1-1/2]x[1-1/3]x[1-1/4]x..........[1-1/18]x[1-1/19]x[1-1/20]
b)1/1/2x1/1/3x1/1/4x1/1/5........x1/1/2005x1/1/2006x1/1/2007
a,
=1/2x2/3x3/4x...x17/18x18/19x19/20
=1/20
b,
tính nhanh tìm A
A=1/2.1/3x1/4x1/5x1/6x1/7x1/8x.......x1/7943297
tính:
a).1/2x1/4x1/6
b).1/2x1/4:1/6
c).1/2:1/4x1/6
ai làm đầy đủ phép tính đáp án mik tick 2!!!nói luôn ra đáp án mik ko tick
Tính
a ) 1/2 x 1/4 x 1/6
= 1/8 x 1/6
= 1/48
b ) 1/2 x 1/4 : 1/6
= 1/8:1/6
3/4
c ) 1/2 : 1/4 x 1/6
= 2 x 1/6
= 1/3
tk mk nha ( nếu đúng )
hihi mơn nha !!!!!!!!!
a, : 1/2 x 1/4 x 1/6 = 1/8 x 1/6 = 1/48
b, ; 1/2 x 1/4 : 1/6 = 1/8 : 1/6 = 6/8 = 3/4
c, 1/2 : 1/4 x 1/6 = 4/2 x 1/6 = 4/12 = 1/3
Tính nhanh 3/4x1/2x4/5x2/3:1/5=
3/4 x 1/2 x 4/5 x 2/3 : 1/5
=1/2 x 2/3 x 3/4 x4/5 : 1/5
=1 x 2 x 3 x 4 / 2 x 3 x 4 x 5 : 1/5
=1/5 : 1/5
=1
Tính nhanh :a)2/5+4/5 nhân 5/2
b)2008/2009-2009/2008+1/2009+2007/2008