Question

Numerle a,b,c sunt direct proportionate cu 4,5 si 8 si 2a+3b+5c=630.Aflati a,b,c.

Answer 1

a/4=b/5=c/8=K
--> a=4k b=5k c=8k

2x4k +3x5k+5x8k=630
63k=630 
k=10
-> a =40
b=50
c=80

Answer 2

[tex]\sf \{a,b,c\}~d.p~\{4,5,8\} \longrightarrow \frac{a}{4}= \frac{b}{5}= \frac{c}{8}=k \\ a=4k \\ b=5k \\ c=8k \\ 2a+3b+5c=630 \\ 2*4k+3*5k+5*8k=630 \\ 8k+15k+40k=630 \\ 63k=630 \\ \underline{k=10} \\ a=4*10 \\ \boxed{\sf a=40} \\ b=5*10 \\ \boxed{\sf b=50} \\ c=8*10 \\ \boxed{\sf c=80}[/tex]