Question

if 3a+2b=5c,then find the value of 27a³+8b³-125c³,if abc=0

Answer 1

a³+b³+c³-3abc=(a+b+c)(a²+b²+c²-ab-bc-ac)

also,
abc=0
and
(3a+2b-5c)=0
therefore

27a³+8b³-125c³=0