Question

Efectuati:
a) (- 3/55):(9/10) -(- 5/22)×4/5 ;
b) (- 9/10) :(+ 18/25) -(+ 3/5) :21/20;
c) (+3 1/13): (- 32/26)- (- 9/14)×(+ 21/27);
d) 2 15/55 : (-6 1/4)- (- 15/18) :1 2/3;

Answer 1

a) (- 3/55):(9/10) -(- 5/22)×4/5 =
= (- 3/55) ×(10/9) + 5/22×4/5 =
= (- 1/11) ×(2/3) + 1/11)×2/1 =
= - 2/33+  2/11 =
= - 2/33+  6/33 =
= 4/33

b) (- 9/10) :(+ 18/25) -(+ 3/5) :21/20=
=(- 9/10) ×(25/18) -(+ 3/5) ×20/21=
=(- 1/2) ×(5/2) -(+ 1/1) ×4/7=
=-5/4 - 4/7=
=(-35-16)/28=-51/28

c) (+3 1/13): (- 32/26)- (- 9/14)×(+ 21/27)=
= (+40/13)× (- 26/32)+ ( 1/2)×(+ 1/1)=
= (+5/1)× (- 1/2)+ ( 1/2)×(+ 1/1)=
= -5/2 +  1/2=
=-4/2=-2

d) 2 15/55 : (-6 1/4)- (- 15/18) :1 2/3=
=125/55 : (-25/4)- (- 15/18) : 5/3=
=25/11 × (-4/25)- (- 15/18) ×3/5=
=1/11 × (-4/1)- (- 3/6) ×1/1=
=-4/11+3/6=
=(-24+33)/66=
=-9/66=
=-3/22