How do you solve #t^3 - 3t^2 - 10t = 0#?

Question

921 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-02-27T10:24:07

#t=0" ; "t=+5" ; "t=-2#

First notice that #t# is in common to all elements on the left

Factor out #t# giving

#t(t^2-3t-10)=0#

Notice that #2xx5=10" and that "5-2=3#

But we have #-3t" so we must have "2-5=-3#

#t(t-5)(t+2)=0#

So for this to be true then #t# can take on 3 values as follows:

#t=0" ; "t=+5" ; "t=-2#