a. A=[ 2/7.( 1/4 - 1/3 ) ] : [ 2/7 ( 1/3 - 2/5 ) ] = ( 1/4 - 1/3 ) : ( 1/3 - 2/5 = 1 1/4

b. B = 3/4 ( 1/5 - 2/7 - 1/3 + 2/7 ) = 3/4 ( 1/5 - 1/3 )

1/5( 2/7 + 1/3 ) - 1/3 ( 2/7 + 1/3 ) = ( 1/5 - 1/3 ) ( 2/7 + 1/3 ) = 1 11/52

a. A = 3/5 . 6/7 + 3/7 . 3/5 - 2/7 . 3/5

= 3/5 .( 6/7 + 3/7 - 2/7

= 3/5

b. B = ( -13 . 2/5 + -2/9 . 2/5 + 2/5 .11/9 ) . 5/2

= ( -13 - 2/9 + 11/9 ) . 2/5 .5/2 = -13 + ( 11/9 - 2/9 ) = -12

c. C = ( -4/5 + 5/7 ) .3/2 + ( -1/5 + 2/7 ) . 3/2

= (-4/5 + 5/7 + -1/5 + 2/7 ) .3/2

= ( -4/5 + -1/5 ) + ( 5/7 + 2/7 ) .3/2

= 0

d. D = 4 : ( 1/15 - 10/15 ) + 4/9 : ( 2/22 - 5/22)

= 4/9 : -3/5 + 4/9 : -3/22 = 4/9 - 5/3 + 4/9 . -22/3

= 4/9 .( -5/3 + -22/3 ) = 4/9 . -27/3

=-4

a. P= 2/3 + 1/4 + 3/5 - 7/45 + 5/9 + 1/12 + 1/35 = ( 2/3 + 1/4 + 1/12) + ( 5/9 -7/45 ) + 3/5 + 1/35 = 1+ 4/5 + 3/5 + 1/35 = 2 1/35

b. Q = ( 5 - 6 -2 ) + ( - 3/4 - 7/4 + 5/4 ) + ( 1/5 + 8/5 - 16/5 ) = - ( 3+ 5/4 + 7/5 ) = - 113/20

a. A= (1/3 + 2/3) - ( 8/15 + 7/15) + ( -1/7 + 1 1/7) = 1-1+1=1

b. B = ( 0.25 - 1 1/4 ) + (3/5 + 2/5) - 1/8

= ( 1/4 -1 -1/4 ) + 1 - 1/8

= -1/8

1B 2C 3A 4A

tick cho mình nhé :)))))

:))))))))

bằng 955

hi

chữ số 5 thuộc hàng chục nhé!!! :)