+613 Find $t$ if the expansion of the product of $x^3$ and $x^2 + tx$ has no $x^2$ term.
+1952 First, let's multiply it out. x3(x2+tx)=x5+tx4.
As you can see, there is no x^2 term in this expansion.
This means t can be pretty much anything we want as long as it doesn't contain x^-2 in it!
Thanks! :)
