Find t if the expansion of the product of x^3 - 4x^2 + 5x - 5 and x^2 + tx - 7 has no x^2 term.
what are the x^2 terms
-4x^2*( -7) + 5x(tx) + -5(x^2)
so what is the coefficient of x^2 in terms of t ?
