Okay, according with the identities of parallelograms we have: AE=CE and BE=DE.
Replacing we obtain:
AE=CE
2x=x+2
2x-x=2
x=2
BE=DE
y+10=4y−8
10+8=4y-y
18=3y
y=18/3
y=6
And considering that BD=BE+DE, we got:
BD=(y+10)+(4y-8)=(6+10)+(4*6-8)=(16)+(24-8)=16+16=32
So, finally we obtain that the length of BD is 32 units.