Question

Daca numerele a si b sunt invers proportionale cu 3 si 4, calculati 3x + 2y/x + 3y

Answer 1

Răspuns:

a/3=b/4=k

A=3k si b=4k

9k+8k/x+3y

Answer 2

(a,b ) i p ( 3, 4 ) => 3a=4b=k

3a=k=> a=k/3

4b=k=> b=k/4

(3a+2b)/(a+3b)= (3k/3+2k/4)/(k/3+3k/4)=(k+k/2)/(4k/12+9k/12)=(2k/2+k/2)/(13k/12)=(3k/2)/(13k/12)=3k/2*12/13k=36k/26k=36/26=18/13