Răspuns :
a) 1/12 + 4/5 : ( 1/2 - 1/3 ) =
=1/12 + 4/5 : ( 3-2)/6 =
=1/12 + 4/5 : 1/6 =
=1/12 + 4/5 × 6 =
=1/12 + 24/5 =
=(5+288)/60=
=293/60=
=4,88(3)
b) ( 17/3 : 21/4 ) : 34/7 =
= 17/3 × 4/21 ×7/34 =
= 1/3 × 4/3 ×1/2 =
= 1/3 × 2/3 ×1/1 =
=2/9=0,(2)
c) o,5 x [ 1/3 + 1/4 - 0,1 ( 6 ) ] : 2,5 =
0,1(6)=(16-1)/90=15/90=1/6
0,5=5/10=1/2
2,5=25/10=5/2
=1/2 x ( 4+3-2)/12 × 2/5=
=1/2 x 5/12 × 2/5=
=1/1 x 1/12 × 1/1=
=1/12
=1/12 + 4/5 : ( 3-2)/6 =
=1/12 + 4/5 : 1/6 =
=1/12 + 4/5 × 6 =
=1/12 + 24/5 =
=(5+288)/60=
=293/60=
=4,88(3)
b) ( 17/3 : 21/4 ) : 34/7 =
= 17/3 × 4/21 ×7/34 =
= 1/3 × 4/3 ×1/2 =
= 1/3 × 2/3 ×1/1 =
=2/9=0,(2)
c) o,5 x [ 1/3 + 1/4 - 0,1 ( 6 ) ] : 2,5 =
0,1(6)=(16-1)/90=15/90=1/6
0,5=5/10=1/2
2,5=25/10=5/2
=1/2 x ( 4+3-2)/12 × 2/5=
=1/2 x 5/12 × 2/5=
=1/1 x 1/12 × 1/1=
=1/12