Question

a) 2/3 + -1/6

b) 5/4 - 3/16

c) 1/2 + (4/5 - 1/2)

d) (0.5 - 3/4) × ( 1/5 - 0.4)

e) 3/5 × 7/13 - 3/5 . 18/13

Answer 1

a. 2/3+ -1/6

=4/6+ -1/6 = 1/2

b.5/4 - 3/16

=20/16-3/16 = 17/16

c.1/2+ (4/5 - 1/2)

= 1/2+ 4/5 -1/2= 1/2- 1/2 +4/5

=0+4/5= 4/5

d. (0.5-3/4) . (1/5 - 0.4)

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

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

= 1/4 . 1/5= 1/20

e. 3/5 . 7/13 - 3/5. 18/13

= 3/5. (7/13 - 18/13)

= 3/5. -11/13= -33/65

#hoctot

Answer 2

`a)2/3+ -1/6=(2xx2)/(3xx2)+ -1/6=4/6+ -1/6=1/2`

`b)5/4-3/16=20/16-3/16=17/16`

`c)1/2+(4/5-1/2)=1/2+4/5-1/2=1/2-1/2+4/5=0/4+4/5=4/5`

`d)(0,5-3/4)xx(1/5xx0,4)=(1/2-3/4)xx(1/5-2/5)=(2/4-3/4)xx(1/5-2/5)=-1/4xx-1/5=1/20`

`e)3/5xx7/13-3/5xx18/13`

`=3/5xx(7/13-18/13)`

`=3/5xx11/13`

`=33/65`

$#Lani2011$

Chức bn học tốt