Question

determinati numerele x y z stiind ca sunt direct proportionale cu 0,25, 0,(3) si 0,5
iar xy + yz + xz = 216

Answer 1

0.25 =25/100 =1/4
0.(3) =3/9 =1/3
0.5 =5/10 =1/2
x :1/4 =Y:1/3 =z:1/2 =  k
=> x =k/4
    y =k/3
  z =k/2
xy+yz+xz =216
k/4*k/3+k/3*k/2+k/4*k/2 =k^2/12+k^2/6+k^2/8 =216    numitor 24
2k^2+4k^2+3k^2 =5184
9k^2 =5184
k^2 =5184:9 =576
 k =24

x =k/4 =24/4 =6
y =k/3 =24/3 =8
x =k/2 =24/2 =12