Question

fie numerele rationale a , b , c , d utilizati factorul comun si relatiile date
a) daca a*b=5/12 si a*c=7/18 calculati a*(b+c)
b) daca a*c=11/15 si b*c =13/24 calculati (a-b)*c
c) dacaa=4/9 b+c=9/20 calculati a*b+2*a*c-a*d
d) daca a*b=5/12 a*c =9/20 a*d=7/15 calculati a*(b+c+d) si a*(b+c-d)
VA ROG REPEDE!!!!!

Answer 1

a) daca a*b=5/12 si a*c=7/18 calculati a*(b+c)
a(b+c)=a*b+a*c=5/12+7/18=(15+14)/36=29/36

b) daca a*c=11/15 si b*c =13/24 calculati (a-b)*c
(a-b)*c=a*b-b*c=11/15-13/24=(11*8-13*5)/120=(88-65)/120=23/120

c) este incomplet

d) daca a*b=5/12 a*c =9/20 a*d=7/15 calculati a*(b+c+d) si a*(b+c-d)
a*(b+c+d) =a*b+a*c+a*d=5/12+9/20+7/15=(5*5+9*3+7*4)/60=(25+27+28)/60=
=80/60=4/3
a*(b+c-d)=a*b+a*c-a*d=5/12+9/20-7/15=(5*5+9*3-7*4)/60=(25+27-28)/60=
=24/60=2/5