Question

fie proportile a supra b = 1 supra 2 si c supra b = 3 supra 2,cu a,b,c apartine N
a) demonstreaza ca: a+2b+c supra b =4
b) stiind ca: a+c=6 afla numarul b

Answer 1

$\frac{a}{b} = \frac{1}{2} = > \frac{a}{1} = \frac{b}{2} = k$
a=k
b=2K
$\frac{c}{b} = \frac{3}{2} = > \frac{c}{3} = \frac{b}{2} = > c = 3k$
$\frac{k + 4k + 3k }{2k} = \frac{8k}{2k } = \frac{8}{2} = 4$
a+c=6
4k=6
k=1,5
a=1,5
b=3
c=4,5