👤
a fost răspuns

Dau coroana!
Va rog explicati


Dau Coroana Va Rog Explicati class=

Răspuns :

Uite de exemplu:a,b,c sunt direct proportionale cu 2,4,5,iar suma lui a+b+c=33.
Formula e asa:a supra 2=b supra 4=c supra 5=k
a=2k. b=4k. c=5k
Din relatia a+b+c=33 rezulta:
2k+4k+5k=33(inlocuiesti cu cele de sus)
11k=33
K=33 supra 11
K=3 acum inlocuiesti k cu 3
a=2*3=6. b=4*3=12. c=5*3=15
Adunate trebuie sa.ti dea 33(asa te verifici)
7.
a)a/2=b/3=c/6=k
a=2k =>4=2k =>k=2
=>b=6
=>c=12
b)a/4=9b/5=5c/3=k
a=4k
9b=5k =>90=5k =>k=18
=>a=72
=>c=54/5
c)a/6=5b/6=5c/3=k
c=6/10=3/5 =>k=1
=>a=6
=>b=6/5
d)a/4=b/6=c/5=k
a=4k
b=6k
c=5k
4k+6k=30
10k=30 =>k=3
=>a=12
=>b=18
=>c=15

8.
a)a/3=b/4=c/8=k
a=3k
b=4k
c=8k
Daca avem k=2 
=>a=6
=>b=8
=>c=16
b)a/5=2b/3=c/4=k
a=5k
b=3k/2
c=4k
Daca avem k=1/5
=>a=1
=>b=3/10=0,3
=>c=4/5
c)2a=9b/4=c/6=k
a=k/2
b=4k/9
c=6k
Daca avem k=1/8
=>a=1/16
=>b=1/18
=>c=3/4
d)9,(6)=9 intregi 6/9=87/9
0,2(1)=(21-2)/90=19/90
10a/3=9b/87=8c/3=k
a=3k/10
b=87k/9
c=3k/8
Daca avem k=19/90
=>a=57/900
=>b=1653/810
=>c=19/240