Question

Numerele a si b sunt direct proportionale cu 3 si 4, iar 2a + 3b= 3240. Determinati numerele a si b.

Answer 1

a,b d.p cu 3,4⇒a/3=b/4=k    a=3k   b=4k
2a+3b=3240
2*3k+3*4k=3240
6k+12k=3240
18k=3240
k=180
a=3*180=540
b=4*180=720

Answer 2

{a, b} d.p. {3,4}
a/3=b/4=k => a=3k , b=4k
2a+3b=3240 => 6k+12k=3240   
                           18k=3240
                            k=180
=> a=3k, a=3*180 , a=540
=> b=4k, b=4*180 , b=720