Question

am nevoie de ajutor la ex 4 ​

Answer 1

Răspuns:

{a;b;c} d.p.{3;5;7}

a/3=b/5=c/7=k=>

a=3k; b=5k ;c=7k

a)P=a+b+c;c=21cm=>21=7k;k=3cm

b=5k=15cm;a=3k=9cm

P=9+15+21=45cm

b)P=60cm

3k+5k+7k=60

15k=60=>k=4cm

a=3k=12cm;b=5k=20cm;c=7k=28cm

c)c-a=8cm=> c=a+8cm

c/7=a/3

=>(a+8)/7=a/3=>3a+24=7a ;24=4a=>a=6cm

c=14cm

b/5=c/7=>b/5=2=>b=10cm