Question

Trei numere sunt direct proportionale cu 12,13 si 15.Daca suma celor trei numere este mai mica decat 81,aflati cele trei numere. Va rog frumos,repede!!

Answer 1

{a,b,c}dp.{12,13,15}
$\frac{a}{12} =\frac{b}{13}= \frac{c}{15} =k$
a=12k
b=13k
c=15k
a+b+c<81
12k+13k+15k<81
40k<81
40k≤80
k≤2
k∈{0,1,2}

a∈{12×0,12×1,12×2}
a∈{0,12,24}

b∈{13×0,13×1,13×2}
b∈{0,13,26}

c∈{0×15,1×15,2×15}
c∈{0,15,30}