Question

Determinati a,b,c stiind ca sunt direct proportionale cu 9,11,14 si a+b+c=680

Answer 1

direct proportionale inseamna
a/9=b/11=c/14=k
a/9=k  =>a=9k
b/11=k  =>b=11k
c/14=k  =>c=14k

dar a+b+c=680  inlocuim
9k+11k+14k=680
34k=680
k=680:34
k=20
a=9k  =>a=9x20=180
b=11k  =>b=11x20=220
c=14k  =>c=14x20=280

Answer 2

a/9=b/11=c/14 = (a+b+c) / (9+11+14= 680 / 34 = 20

=> a=  9*20=180 
    
      b=11*20=220
  
      c=14*20=280
                   ------------ suma lor ...
                     680  (A)