Question

5a=8b=3c và a-2b+c=34

Answer 1

a - 2b + c = 34

=>8b/5 - 2b + 8b/3 = 34

=>24b/15 - 30b/15 + 40b/15 = 510/15

=>64b/15 - 30b/15 = 510/15

=>b = 510/15:34/15

=>b =15

=>a = 15 . 8/5 = 24

c = 15 . 8/3 = 40 

 

Answer 2

5a=8b=3c => a/(1/5) =b/(1/8) =c/(1/3) 
=> a/(1/5) =2b/(1/4) =c/(1/3) = (a-2b+c)/ (1/5 -1/4 +1/3)=34/(17/60)=120 
a/(1/5) =120 =>a=120x1/5=24 
2b/(1/4) =120 hay 8.b=120 =>b=120:8=15 
c/(1/3) =120 =>c=120x1/3=40