Question

Nr x si y sunt direct proportionale cu4 si 5.

a)Aflati cat la suta reprezinta nr x din nr y
b) daca x+y=54 determinati x si y

Answer 1

x/4=y/5=k
x=4k
y=5k
x/y=a/100
4k/5k=a/100
4/5=a/100
a=80%
deci numarul x reprezinta 80% din y
b) x+y=54
4k+5k=54
9k=54
k=54:9=6 deci
x=4k=4.6=24
y=5k=5.6=30
24+30=54