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1 + 1 : 2 x 1 + 5 x 6 - 4
=1 + 1 : 2 + 30 - 4
= 1 + 0,5 + 30 - 4
= 1,5 + 28
= 29,5
7,7 x 0,25 - 0,1 + 2,4 x 0,25
= ( 7,7 + 2,4 ) x 0,25 - 0,1
= 10,1 x 0,25 - 0,1
= 2,525 - 0,1
= 2,425
x + 1/2 x 1/3 = 3/4
x + 1/6 = 3/4
x = 3/4 - 1/6
x = 7/12
1/2x1/3+1/3-1/4+1/4x1/5
= 1/2-1/3+1/3-1/4+1/4-1/5
=1/2-1/5
=3/10. (1/2x1/3= 1/2x3)
1/2x1/3+1/3-1/4+1/4x1/5 = 1/2-1/3+1/3-1/4+1/4-1/5 =1/2-1/5 =3/10. (1/2x1/3= 1/2x3)
a) \(=5,6\cdot\left(4+3+2+1\right)\\ =5,6\cdot10=56\)
b) \(=5\)
a)5,6 x 4 + 5,6 x3 + 5,6 x 2 + 5,6
=5,6x(4+3+2+1)
=5,6x10
=56
b) =5
(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
(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