Question

determinati numerele x si y stiind că sunt invers proportionate cu 0,(3) si 0,25,air media lor aritmetica este 14

Answer 1

(x+y)/2=14
x+y=14·2
x+y=28
0,(3)=3/9=simpli=1/3
0,25=25/100=simplif=1/4
{x,y}ip{1/3,1/4}
x/3=y/4=k
x/3=k⇒  x=3k
y/4=k⇒  y=4k
3k+4k=28
7k=28
k=2/7
k=4
x=3k=3·4=12
y=4k=4·4=16
12+16=28