Question

a,b,c direct proportional 3,2,5 stiind ca perimetrul este 420

Answer 1

a=2k
b=3k
c=5k

a+b+c=420
2k+3k+5k=420
10k=420
k=420:10
k=42

a=3*42=126
b=2*42=84
c=5*42=210

Answer 2

[tex] \frac{a}{3} = \frac{b}{2} = \frac{c}{5} =420 \\ \frac{a+b+c}{3+2+5} = \frac{420}{10} \\ \frac{a}{3} = \frac{420}{10} =\ \textgreater \ a= \frac{420*3}{10} =\ \textgreater \ a= \frac{1.260}{10} =\ \textgreater \ a=126 \\ \frac{b}{2} = \frac{420}{10} =\ \textgreater \ b= \frac{420*2}{10} =\ \textgreater \ b= \frac{840}{10} =\ \textgreater \ b=84 \\ \frac{c}{5} = \frac{420}{10} =\ \textgreater \ c= \frac{420*5}{10} =\ \textgreater \ c= \frac{2.100}{10} =\ \textgreater \ c=210[/tex]