Answer :
it bisects so DE=EF
DE=5y
EF=13y-8
so
5y=13y-8
minus 13y both sides
-8y=-8
divide both sides by -8
y=1
DE=5y=5(1)=5
DE=EF=5
DF=DE+EF=5+5=10
DE=5
EF=5
DF=10
DE=5y
EF=13y-8
so
5y=13y-8
minus 13y both sides
-8y=-8
divide both sides by -8
y=1
DE=5y=5(1)=5
DE=EF=5
DF=DE+EF=5+5=10
DE=5
EF=5
DF=10