Question

Clalculati ” (5 sub 21 +3sub 35 ) Ori (-3 sub 34 +2 sub 51 )

Answer 1

5/21+3/35

aduc la acelasi numitor

21=3x7

35=7x5

cmmdc=3x5x7=15x7=105

deci 5/21 il amplific cu 5= 5x5/105=25/105

          3/35 il amplific cu3 = 3x3/105=9/105

deci 5/21+3/35=25/105+9/105=34/105

acum a doua paranteza

-3/34+2/51 aduc la acelasi numitor

34=2x17

51=3x17

cmmdc= 2x3x17=6x17=102

deci -3/34 il amplific cu 3= -3x3/102=-9/102

         2/51 il amplific cu 2= 2x2/102= 4/102

deci -3/34+2/51= -9/102+4/1-2=-5/102

astfel exercitiul (5/21+3/35) ori (-3/34+2/51)=34/105 ori -5/102=

(pe digonale 34 se simplifica cu 102 si in loc de 34 scriu 1 iar in loc de 102 scriu 3)= 1/105 ori -5/3 (pe diagonal 105 se simplifica cu 5 si in loc de 105 scriu 21 iar in loc de 5 scriu 1)=1/21 ori -1/3=(1x(-1)/(21x3)=-1/63